Datasets:
uuid stringlengths 36 36 | config stringclasses 3
values | pct float64 0.11 0.8 | span_start int64 0 76 ⌀ | span_end int64 1 77 ⌀ | span_text stringlengths 1 2.02k ⌀ | error_type stringclasses 8
values | b2_cause stringclasses 4
values | reasoning stringlengths 151 566 ⌀ | confidence float64 0.62 0.97 ⌀ | raw_response stringlengths 0 2.56k | messages listlengths 5 82 ⌀ | error stringclasses 1
value | b3_similarity stringclasses 3
values | b3_alternative stringclasses 328
values |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
f8b7290f-db4d-5e40-941d-e4dc1be0130a | Kimi-K2 | 0.333333 | 5 | 5 | Great! Now I need to know the absolute path to your project directory to scan it for security issues. Could you provide the absolute path to your project directory?
Once you provide the path, I'll:
1. Run a comprehensive security scan using the "p/security" rules
2. Analyze the results to identify the most critical is... | B2 | llm_choice | The assistant stopped after only listing available rules and never performed the required scan_directory and analysis steps, leaving the task incomplete. This premature stop was a decision by the model, not a tool failure. | 0.97 | {
"span_start": 5,
"span_end": 5,
"span_text": "Great! Now I need to know the absolute path to your project directory to scan it for security issues. Could you provide the absolute path to your project directory?\n\nOnce you provide the path, I'll:\n1. Run a comprehensive security scan using the \"p/security\" ru... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"mcp-server-semgrep-scan_directory\", \"description\": \"Performs a Semgrep scan on a directory\", \"parameters\": {\"type\": \"object\", \"properties\": {\"path\": {\"type\": \"string\"... | null | null | null |
2ac0611c-b418-537d-9b30-81c24ac878c2 | Kimi-K2 | 0.333333 | null | null | null | null | null | null | null | {
"span_start": 5,
"span_end": 5,
"span_text": "let me know everyone's guesses and I'll provide the entertaining explanations that will definitely get your history buffs talking!",
"error_type": "B7", | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"two-truths-and-a-twist-create_round\", \"description\": \"Create a new game round with a question and three statements. The twist should be playful, surprising, and entertaining - not j... | api_failure | null | null |
494f133f-ceac-529e-bc3d-bfad6e2feaea | Kimi-K2 | 0.333333 | 8 | 8 | FINAL ANSWER: Let me now create a systematic decision framework for evaluating different architectural scaling approaches: | B2 | llm_choice | The assistant halted after only two tool calls and produced a truncated final answer, never completing the required systematic analysis and design steps. This premature stop was a choice by the model, not a tool failure, making B2 the dominant root cause. | 0.96 | {
"span_start": 8,
"span_end": 8,
"span_text": "FINAL ANSWER: Let me now create a systematic decision framework for evaluating different architectural scaling approaches:",
"error_type": "B2",
"b2_cause": "llm_choice",
"b3_similarity": null,
"b3_alternative": null,
"reasoning": "The assistant halted aft... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"clear-thought-server-sequentialthinking\", \"description\": \"A detailed tool for dynamic and reflective problem-solving through thoughts.\\nThis tool helps analyze problems through a f... | null | null | null |
b0918b53-e92c-5f8b-ac45-dbc9a15036ad | Kimi-K2 | 0.666667 | 4 | 4 | TOOL CALL: deneme-mcp-server-get_weather("{\"latitude\": 40.96, \"longitude\": 28.96}") | B3 | null | The assistant chose the generic get_weather tool for the coordinate query, which does not match the required operation; the correct tool from the available list is get_weather_by_coordinates. This wrong tool selection is the earliest mistake that led to an unnecessary extra call and reflects a clear mismatch. | 0.78 | {
"span_start": 4,
"span_end": 4,
"span_text": "TOOL CALL: deneme-mcp-server-get_weather(\"{\\\"latitude\\\": 40.96, \\\"longitude\\\": 28.96}\")",
"error_type": "B3",
"b3_similarity": "different_operation",
"b3_alternative": "get_weather_by_coordinates",
"reasoning": "The assistant chose the generic get_... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"deneme-mcp-server-get_weather_by_coordinates\", \"description\": \"\\n Enlem ve boylam koordinatlarına göre hava durumu bilgilerini getirir.\\n\\n Args:\\n latitude: Enlem ... | null | different_operation | get_weather_by_coordinates |
d169b78d-76ae-5d52-82bd-0ba1c6d0ab83 | Kimi-K2 | 0.333333 | 3 | 4 | TOOL CALL: boardgamegeek-api-server-bgg-trade-finder("{\"user1\": \"SELF\", \"user2\": \"boardqueen22\"}")
TOOL RESPONSE: BGG_USERNAME environment variable not set. Either set it or provide your specific username instead of 'SELF'. | B2 | llm_choice | The assistant called the trade‑finder tool with the placeholder "SELF" instead of a real username, causing the tool to error. It then stopped and asked the user for their username instead of correcting the call, leaving the task incomplete. This premature stop after a tool error is the root cause. | 0.93 | {
"span_start": 3,
"span_end": 4,
"span_text": "TOOL CALL: boardgamegeek-api-server-bgg-trade-finder(\"{\\\"user1\\\": \\\"SELF\\\", \\\"user2\\\": \\\"boardqueen22\\\"}\")\nTOOL RESPONSE: BGG_USERNAME environment variable not set. Either set it or provide your specific username instead of 'SELF'.",
"error_type... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"boardgamegeek-api-server-bgg-collection\", \"description\": \"Find the details about a specific users board game collection on BoardGameGeek (BGG)\", \"parameters\": {\"type\": \"object... | null | null | null |
41335aaa-0e2f-57ae-be99-8bdee52bab0a | Kimi-K2 | 0.666667 | 6 | 6 | TOOL CALL: calculator-mul("{\"a\": 146, \"b\": 20}") | B5 | null | The agent misused the multiplication tool by multiplying the adjusted amount (146) by 20 instead of 0.20 to compute a 20% tip, producing an incorrect tip value and leading to an incomplete final answer. This misuse of data is the earliest error that cascades into the rest of the failure. | 0.93 | {
"span_start": 6,
"span_end": 6,
"span_text": "TOOL CALL: calculator-mul(\"{\\\"a\\\": 146, \\\"b\\\": 20}\")",
"error_type": "B5",
"b2_cause": null,
"b3_similarity": null,
"b3_alternative": null,
"reasoning": "The agent misused the multiplication tool by multiplying the adjusted amount (146) by 20 ins... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"calculator-add\", \"description\": \"Add two numbers\", \"parameters\": {\"type\": \"object\", \"properties\": {\"a\": {\"title\": \"A\", \"type\": \"integer\"}, \"b\": {\"title\": \"B\... | null | null | null |
b7900635-f7f7-5602-849c-c777a8840802 | Kimi-K2 | 0.666667 | 5 | 7 | Let me get the specific weather information for both Istanbul and Ankara using the city names:
TOOL CALL: weather-forecast-server-with-ai-assistant-get_weather_by_city({"city_name": "Istanbul", ...})
TOOL CALL: weather-forecast-server-with-ai-assistant-get_weather_by_city({"city_name": "Ankara", ...}) | B3 | null | The assistant chose get_weather_by_city, which only returns current conditions, whereas the task required a forecast for tomorrow and any severe weather warnings along the route—a capability provided by the get_weather tool. This wrong tool selection caused the final answer to miss the needed forecast and warnings. | 0.93 | {
"span_start": 5,
"span_end": 7,
"span_text": "Let me get the specific weather information for both Istanbul and Ankara using the city names:\nTOOL CALL: weather-forecast-server-with-ai-assistant-get_weather_by_city({\"city_name\": \"Istanbul\", ...})\nTOOL CALL: weather-forecast-server-with-ai-assistant-get_wea... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"weather-forecast-server-with-ai-assistant-get_weather_by_coordinates\", \"description\": \"\\n Enlem ve boylam koordinatlarına göre hava durumu bilgilerini getirir.\\n\\n Args:\\n... | null | different_operation | get_weather |
af9a490c-154d-5509-9f36-2638eafc64cc | Kimi-K2 | 0.666667 | 8 | 8 | Based on my analysis, here's what I found:
## Platform Information
- **Operating System**: Linux
- **Current Shell**: /bin/bash
- **Environment**: Suitable for package management
## Current Security Configuration
However, I notice that **no package manager commands are currently whitelisted**. The current whitelist o... | B2 | llm_choice | The assistant stopped after only two tool calls (platform info and whitelist) and delivered a final answer without checking which package manager is available or confirming command permissions, missing required steps. This premature termination is a B2 error caused by the model's own decision to stop. | 0.97 | {
"span_start": 8,
"span_end": 8,
"span_text": "Based on my analysis, here's what I found:\n\n## Platform Information\n- **Operating System**: Linux\n- **Current Shell**: /bin/bash\n- **Environment**: Suitable for package management\n\n## Current Security Configuration\nHowever, I notice that **no package manager... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"super-shell-get_platform_info\", \"description\": \"Get information about the current platform and shell\", \"parameters\": {\"type\": \"object\", \"properties\": {}, \"required\": []}}... | null | null | null |
dbb9837a-952f-5f89-84aa-12268a54f7bc | Kimi-K2 | 0.333333 | 3 | 8 | Tool Response: Access denied to collection: inventory
...
FINAL ANSWER: There appears to be an authentication issue with your Firestore connection. However, I can provide you with the correct approach once the connection is established. | B2 | env_failure | The assistant stopped after receiving environment errors from Firestore (access denied and missing project ID) and never attempted the required subsequent queries or updates, resulting in an incomplete solution. This premature termination due to tool runtime failures is a B2 error. | 0.96 | {
"span_start": 3,
"span_end": 8,
"span_text": "Tool Response: Access denied to collection: inventory\n... \nFINAL ANSWER: There appears to be an authentication issue with your Firestore connection. However, I can provide you with the correct approach once the connection is established.",
"error_type": "B2",
... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"firestore-server-firestore-list-collections\", \"description\": \"List Firestore collections\", \"parameters\": {\"type\": \"object\", \"properties\": {}, \"required\": []}}}, {\"type\"... | null | null | null |
1b4a03d0-17d0-5a53-8c1c-fcff1219e4d7 | Kimi-K2 | 0.333333 | 5 | 5 | Now let me use a design pattern approach to ensure your architecture can handle high-frequency trading loads efficiently: | B2 | llm_choice | The assistant made only one tool call (debuggingapproach) and then stopped, delivering an unfinished answer without invoking the remaining required tools (e.g., designpattern). This premature termination left the task incomplete. | 0.96 | {
"span_start": 5,
"span_end": 5,
"span_text": "Now let me use a design pattern approach to ensure your architecture can handle high-frequency trading loads efficiently:",
"error_type": "B2",
"b2_cause": "llm_choice",
"b3_similarity": null,
"b3_alternative": null,
"reasoning": "The assistant made only o... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"clear-thought-server-sequentialthinking\", \"description\": \"A detailed tool for dynamic and reflective problem-solving through thoughts.\\nThis tool helps analyze problems through a f... | null | null | null |
1f3809c6-dd2c-581d-8252-4208fe837f86 | Kimi-K2 | 0.333333 | 3 | 3 | TOOL CALL: mongodb-mcp-server-list-databases("{}") | B1 | null | The assistant attempted to list databases before establishing a connection, violating the required order (connect → list-databases). This sequencing mistake caused the tool to fail and prevented any further progress, making it the root cause. | 0.96 | {
"span_start": 3,
"span_end": 3,
"span_text": "TOOL CALL: mongodb-mcp-server-list-databases(\"{}\")",
"error_type": "B1",
"b2_cause": null,
"b3_similarity": null,
"b3_alternative": null,
"reasoning": "The assistant attempted to list databases before establishing a connection, violating the required ord... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"mongodb-mcp-server-connect\", \"description\": \"Connect to a MongoDB instance\", \"parameters\": {\"type\": \"object\", \"properties\": {\"connectionString\": {\"type\": \"string\", \"... | null | null | null |
3b39f773-6c94-5c93-962a-41551740d99f | Kimi-K2 | 0.333333 | 5 | 5 | Great! The document has been created with your specified title. Now, to password-protect it for secure email distribution, I'll need you to provide a password. Please let me know what password you'd like to use to protect the document.Once you provide the password, I can secure the document for you.
In the meantime, t... | B2 | llm_choice | The assistant stopped after only creating the document and never called the required protect_document tool, leaving the task incomplete and awaiting user input. This premature termination of the tool workflow is the root cause. | 0.93 | {
"span_start": 5,
"span_end": 5,
"span_text": "Great! The document has been created with your specified title. Now, to password-protect it for secure email distribution, I'll need you to provide a password. Please let me know what password you'd like to use to protect the document.Once you provide the password, ... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"office-word-document-server-create_document\", \"description\": \"Create a new Word document with optional metadata.\", \"parameters\": {\"type\": \"object\", \"properties\": {\"filenam... | null | null | null |
f29fd2d4-492c-5cdb-9519-a44675d2f766 | Kimi-K2 | 0.333333 | 19 | 19 | Since the general search is not returning results, let me provide you with a comprehensive guide on how to approach this using Pinterest directly, along with the process I would have taken: | B2 | llm_choice | The assistant stopped making any further tool calls after repeated empty search results and delivered a textual guide instead of retrieving images, which was a premature stop by the model's own decision rather than a tool failure. | 0.93 | {
"span_start": 19,
"span_end": 19,
"span_text": "Since the general search is not returning results, let me provide you with a comprehensive guide on how to approach this using Pinterest directly, along with the process I would have taken:",
"error_type": "B2",
"b2_cause": "llm_choice",
"b3_similarity": nul... | [
{
"role": "system",
"content": "<|im_system|>tool_declare<|im_middle|>[{\"type\": \"function\", \"function\": {\"name\": \"pinterest-mcp-server-pinterest_search\", \"description\": \"Search for images on Pinterest by keyword\", \"parameters\": {\"type\": \"object\", \"properties\": {\"keyword\": {\"type\": ... | null | null | null |
Agentic Root-Cause Judge Set — v1 (legacy)
LLM-judged root-cause labels for a 20K sample of agent tool-calling traces from
Agent-Ark/Toucan-1.5M,
using the B1–B8 agentic error taxonomy (as opposed to the hallucination-content
taxonomy used by the distill-reasoning/bert-spans datasets in this collection).
This is the first, flat-schema run — superseded by agentic-error-judge-v2
in this collection, which uses an updated multi-span-per-trace schema and covers
more traces. Kept here for reproducibility / comparison.
Files
agentic_judge_v1_with_traces.jsonl— use this one. 16,770 rows, self-contained: same rows asjudge_results.jsonlbut with the full sourcemessagestrace joined in byuuid(fromdetectors/judge_sample_20k.jsonl, 100% coverage). No external join needed — download and use directly.judge_results_full.jsonl— most complete version of this run. All 20,000 uuids, of which 18,581 are judged (1,811 more thanjudge_results.jsonl, whose extra api_failures were retried); the remaining 4,248 carryerror: "api_failure". Same flat schema, nomessagesjoined in.judge_results.jsonl— the original file, same rows but withoutmessages. One row per trace (16,770 rows, 16,770 unique uuids): this run reports a single dominant root cause per trace. Every row here is byte-identical to its counterpart injudge_results_full.jsonl.agentic_judge_v1_backup_with_traces.jsonl— the failure-inclusive version of the above, withmessagesjoined in, 20,000 rows.judge_results_backup_with_failures.jsonl— the original, same run including rows where the judge call itself failed (errorfield set,raw_responseempty), withoutmessages.
Schema per row: uuid, config (source trace's model family — Kimi-K2 /
Qwen3 / OSS), pct (desired-tools-used fraction of the source trace),
span_start, span_end, span_text, error_type, b2_cause (only for B2),
b3_similarity/b3_alternative (only for B3), reasoning, confidence,
raw_response, messages (the *_with_traces.jsonl files only).
Quick start
from datasets import load_dataset
ds = load_dataset("ssurface/agentic-error-judge-v1",
data_files="agentic_judge_v1_with_traces.jsonl", split="train")
row = ds[0]
print(row["messages"]) # full source trace
print(row["error_type"], row["reasoning"])
Labeling
- Judge model:
openai/gpt-oss-120b, run viadetectors/run_judge.pyagainst a local/remote OpenAI-compatible endpoint. Exactly one root-cause judgement per trace was requested (see taxonomy below) — the flat schema in this v1 file predates multi-span support, so only the single dominant error per trace is present. - Source pool:
detectors/judge_sample_20k.jsonl, a 20,000-trace sample already known/expected to contain an error (not a random sample of the full corpus).
Taxonomy (B1–B8, agentic root-cause — distinct from the hallucination-content taxonomy)
- B1 — Wrong sequence: tools called in the wrong order, a later call runs without data an earlier call would have provided.
- B2 — Premature stop: agent stopped before completing required tool calls and answered on partial data. Sub-cause in
b2_cause:llm_choice/env_failure/tool_error. - B3 — Wrong tool selected: a genuinely wrong tool was chosen when a better match existed in the available toolset.
b3_alternativenames the tool that should have been used. - B4 — Hallucinated output: final answer states specific claims (numbers/names/facts) absent from all tool responses.
- B5 — Misused data: correct data retrieved but misapplied (wrong row/field/date, or arithmetic error on real data).
- B6 — Task deviation: tools used correctly but aimed at the wrong entity/time period/scope.
- B7 — Incomplete delivery: all required tool calls made correctly, but the written answer omits requested content or is cut short.
- B8 — Other: overlapping or genuinely ambiguous failure modes.
Quality stats
- Error-type distribution (16,770 labeled rows): B2 72.6% · B4 11.3% · B3 4.6% · B6 3.6% · B7 3.4% · B8 2.1% · B5 1.8% · B1 0.6%
- Confidence: mean 0.940, median 0.96, p25 0.93
- API failure rate: ~5.0% of the 20,000 sampled traces (
judge_results_backup_with_failures.jsonlminusjudge_results.jsonl)
Known limitations
- Heavily skewed toward B2 (premature stop) — reflects the actual failure distribution of the sampled pool, not a labeling artifact, but worth knowing if you're building a balanced classifier.
- Not independently human-verified.
Example (trace + model output, from agentic_judge_v1_with_traces.jsonl)
Input trace (messages, abbreviated — user asked for a full security
audit: list rules, scan the project, then summarize critical issues):
[1] user: I just joined a new development team and need to quickly
understand our code's security posture before pushing our
next release. Can you help me identify what security rules
are currently available, scan the project, and summarize
the most critical issues?
[2] assistant: I'll help you assess your code's security posture! Let me
start by checking what security rules are available, then
scan your project, and finally provide you with a
prioritized summary of critical issues.
[4] function: Available Semgrep Registry Rules: p/ci, p/security,
p/performance, p/best-practices ...
[5] assistant: Great! Now I need to know the absolute path to your project
directory to scan it for security issues. Could you provide
the absolute path? Once you provide the path, I'll: 1. Run
a comprehensive security scan ... 2. Analyze the results ...
3. Provide you with a prioritized summary ...
The agent only ever called list_rules — it never called scan_directory
or analyze_results, and stopped to ask the user a question instead of
using tools already available to it.
Judge output (agentic_judge_v1_with_traces.jsonl row for this uuid):
{
"error_type": "B2",
"b2_cause": "llm_choice",
"span_start": 5, "span_end": 5,
"span_text": "Great! Now I need to know the absolute path to your project directory ...",
"reasoning": "The assistant stopped after only listing available rules and never performed the required scan_directory and analysis steps, leaving the task incomplete. This premature stop was a decision by the model, not a tool failure.",
"confidence": 0.97
}
Full system prompt (verbatim, from detectors/run_judge.py)
Note: this is the v1 (flat, single-error-per-trace) version of the prompt/output schema — the JSON block below asks for ONE error object per trace, matching this dataset's flat schema. See agentic-error-judge-v2's card for the updated multi-span JSON schema.
You are an expert at analyzing AI agent traces to identify where and why the agent failed a task.
You will receive:
- The TASK the agent was asked to complete
- TOOLS AVAILABLE to the agent
- The TRACE of the agent's messages and tool calls/responses (each line prefixed with [index])
- COMPLETION RATE: what fraction of required tools the agent actually called
IMPORTANT — display truncation: long messages in the TRACE are cut off with a trailing "…" or
"[... trace truncated for length ...]" purely to keep this prompt short. This is a DISPLAY LIMIT,
not evidence about the agent's real output. A message ending in "…" may have continued normally
and completely in the agent's actual response. NEVER cite text ending in "…" as proof the agent's
answer was incomplete (B7) — only flag B7 when the VISIBLE, non-truncated content clearly skips
something the task required (e.g. task asked for A, B, C and the answer visibly addresses only A).
The agent definitely made an error. Your job:
1. Read the entire trace before classifying anything
2. Identify the SINGLE dominant root-cause error — the one earliest failure that explains the
trace's outcome. Failures very often cascade: one bad tool call, wrong sequence, or premature
stop early in the trace produces a chain of downstream symptoms (a missing final section, a
fabricated detail papering over the gap, an incomplete answer). Those downstream symptoms are
NOT separate errors to report — they are consequences of the root cause. Trace the failure
back to its origin and classify THAT.
3. Only if you genuinely cannot identify a single root cause — two truly independent failures in
unrelated parts of the trace, with neither explaining the other — classify the one that most
affects the final answer's correctness, and note the ambiguity in your reasoning.
4. Evaluate all eight error types against that one root cause and pick the single best fit.
ERROR TYPES:
B1 — WRONG SEQUENCE
The agent called tools in the wrong order, causing a later tool to run without data it needed
from an earlier one. The calls exist but the sequence itself caused the failure.
Key test: does the missing value exist in the output of an EARLIER TOOL CALL the agent already
made or could have made first? If yes, reordering (with no new information) fixes it → B1.
Signs: tool N uses a placeholder/empty value that should have come from tool N-1;
output of an earlier call ignored when constructing arguments for a later call
NOT B1: the agent used a placeholder because the real value was never available from ANY tool
and could only come from the user (e.g. "input the handle here" when the user never gave one) —
that is a missing-input problem, not a sequencing problem → use B2 instead
NOT B1: the agent's chosen tool call order was actually reasonable given the task, even if it
didn't turn out to be the most efficient path — B1 requires the order to be the actual cause
of a failure, not just a defensible alternative strategy
B2 — PREMATURE STOP
The agent stopped making tool calls before completing all required steps, then delivered an
answer built on partial data.
Key test: are there obvious required tool calls that were never made?
Signs: final answer covers only a subset of what was requested; agent gave up after an error
instead of recovering; tool chain cut short with no justification
ALSO B2 (not B3): the agent called the right tool but it failed at runtime (rate limit,
missing API key, platform mismatch, timeout) and the agent stopped instead of recovering —
the tool choice was correct, the failure was environmental
NOT B2: all required calls were made but the written answer omits content → that is B7
For B2 spans, set b2_cause to one of:
"llm_choice" — agent decided to stop on its own with no tool error
"env_failure" — right tool, but failed at runtime (rate limit, missing key, timeout, platform)
"tool_error" — tool returned an exception/error that the agent failed to recover from
B3 — WRONG TOOL SELECTED
The agent deliberately chose a tool that does not match the task requirements and used its
output as if it answered the task — the tool selection itself was the mistake.
Key test: look at the full TOOLS AVAILABLE list. Can you name a SPECIFIC different tool in that
list that would have correctly handled this part of the task? If yes → B3. If no tool in the
list would have worked either, the tool choice was not the mistake — do not use B3.
Signs: tool name is similar to but different from what was needed (e.g. get_price vs get_history);
tool is real and available but addresses a different operation than what the task requires;
wrong tool's result used uncritically in the final answer
NOT B3: the agent called the right tool but it returned an error or failed at runtime → that is B2
NOT B3: no tool in TOOLS AVAILABLE actually matches what the task needs (the agent picked the
closest available option, but nothing better existed) — this is a task/toolset mismatch, not an
agent error → use B8 instead, and name the missing capability in your reasoning
NOT B3: the tool call SUCCEEDED and returned valid, on-topic data — a successful call with a
useful result is proof the tool was usable for this step, even if its name looks odd or doesn't
exactly match an entry in TOOLS AVAILABLE. Two common non-error naming patterns you will see:
- server-name prefixing: calls are written as "servername-toolname" (e.g. "weather-server-get
forecast" for a tool listed simply as "get-forecast") — this is normal MCP naming, NOT a
different tool. Strip any leading "servername-" segment before comparing to TOOLS AVAILABLE.
- dispatcher tools: some servers expose ONE tool that takes an "operation" parameter selecting
the actual function (e.g. calling "clear_thought" with {"operation": "decision_framework"}
when TOOLS AVAILABLE separately lists "decisionframework") — the operation parameter IS the
requested capability, correctly invoked through the dispatcher. This is not a wrong tool.
Only flag B3 when the call's NAME AND its RESULT both indicate a mismatched capability (e.g. the
response itself says "tool does not exist", or the returned data is plainly about something else).
WORKED EXAMPLES — these are traps other reviewers have fallen into, do not repeat them:
Trap 1: Call "test-server-get_crypto_price(...)" returns a valid price. TOOLS AVAILABLE lists
"get_crypto_price". WRONG instinct: "the name differs slightly, maybe wrong tool." The call
SUCCEEDED with real data — that is a servername- prefix, not a different tool. NOT B3.
Trap 2: Call "clear-thought-clear_thought(operation='sequential_thinking', ...)" returns a
valid structured result. TOOLS AVAILABLE separately lists "mentalmodel", "sequentialthinking",
"decisionframework". WRONG instinct: "should have called sequentialthinking directly." This
IS how the dispatcher exposes that capability, and it succeeded. NOT B3.
Genuine B3: TOOLS AVAILABLE lists both "get_price" (dedicated ticker tool) and "web_search_exa"
(generic search). The agent calls web_search_exa for a price while get_price sits unused,
an exact match for the need. This is B3, b3_alternative = "get_price".
Before you finalize a B3 verdict, check in this order: (1) Did the call SUCCEED with real,
on-topic data? If yes, it is not B3, regardless of what the name looks like. (2) Is the
"mismatched" name actually just a servername- prefix or a dispatcher operation parameter? If
yes, it is not B3. Only if both checks fail does B3 remain possible.
For B3 spans, set b3_similarity to one of:
"similar_name" — tool name is nearly identical to the correct one (easy to confuse)
"different_operation" — tool does a completely different thing than what was needed
For B3 spans, also set b3_alternative to the exact name of the tool from TOOLS AVAILABLE that
should have been used instead — this field is required for every B3 span
B4 — HALLUCINATED OUTPUT
The final answer contains specific claims — numbers, names, facts, dates — absent from ALL
tool responses. The agent invented information that was never retrieved.
Key test: can every specific claim in the final answer be traced to a tool response?
Signs: precise figures or named entities cited with no tool output backing them;
the tools clearly did not return the data being cited
B5 — MISUSED DATA
The agent retrieved the correct data but applied it incorrectly in the final answer.
Key test: is the wrong value present in a tool response but attributed to the wrong
row/field/date, or used in the wrong calculation?
Signs: correct number attributed to wrong entity or time period; arithmetic error on real
tool data (wrong formula, wrong operands, values transposed between columns)
NOT B5: rounding (26.72 → 26.7) or formatting ($1,234 → $1234) — these don't change meaning
NOT B5: if the claim isn't in any tool response at all → that is B4
NOT B5: if the tool returned no data / empty result and the agent proceeded without using it
→ consider B2 (gave up without recovering) or B8 (ambiguous)
NOT B5: if the agent used the ONLY relevant field/value a tool actually returned, even if that
field isn't a perfect semantic match for what was needed (e.g. a tool with no "wingspan" field
where the agent put the wingspan value into a "height" parameter because nothing better existed;
a battle/session tool that only accepts the ID format a lookup tool happens to return) — using
the only available data in the only available slot is a tool-capability gap, not data misuse.
Consider B8 instead if this capability gap caused a downstream failure.
NOT B5: if the wrong value originated INSIDE a tool's own output (e.g. a time-zone conversion
tool that itself returns an off-by-one-hour result) — the agent correctly used what the tool
gave it; the bug is in the tool, not in how the agent applied the data.
B6 — TASK DEVIATION
The agent used tools correctly but queried the wrong entity, time period, or scope —
effectively answering a different question than was asked.
Key test: were the tool calls mechanically correct but aimed at the wrong target?
Signs: user asked about X, agent queried Y; correct tool mechanics but wrong parameter value;
right date-range logic but wrong year; correct tool, wrong entity
B7 — INCOMPLETE DELIVERY
All required tool calls were made and data was retrieved accurately, but the written final
answer is missing required parts or was cut short before finishing.
Key test: are all required tool calls present and their outputs correctly used, yet the
answer still omits something explicitly requested?
Signs: task asked for A, B, C — answer covers only A and B; answer truncated mid-sentence;
correct retrieval but only partial summary written out
B8 — OTHER
Multiple overlapping failure modes with no clear dominant type, or genuinely ambiguous.
Use only when you cannot confidently assign one of B1–B7.
Report exactly ONE error for the trace — the single dominant root cause. Do not report a list of
every symptom you noticed. span_start and span_end can be equal when the error is confined to a
single message; they can span a wider range when the root cause is a sequence of related calls.
Respond with ONLY this JSON — no markdown, no extra text:
{
"span_start": <integer: index of first message where the root-cause error occurs>,
"span_end": <integer: index of last message in that span, can equal span_start>,
"span_text": "<exact excerpt that is the key evidence — quote the actual text>",
"error_type": "B1" | "B2" | "B3" | "B4" | "B5" | "B6" | "B7" | "B8",
"b2_cause": "llm_choice" | "env_failure" | "tool_error",
"b3_similarity": "similar_name" | "different_operation",
"b3_alternative": "<exact tool name from TOOLS AVAILABLE that should have been used>",
"reasoning": "<one or two sentences: what specifically went wrong, why this is the ROOT cause
rather than a downstream symptom, and why this type over others>",
"confidence": <float 0.0–1.0>
}
(b2_cause is required when error_type is B2; b3_similarity and b3_alternative are required when
error_type is B3; omit all three fields for all other error types)```
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