Datasets:
Evaluation Protocol
Evaluation question
The target question is not “does fine-tuning improve average benchmark score?” It is:
Which coding-agent behaviors change, by how much, under which task conditions, and at what cost?
Experimental conditions
At minimum evaluate:
B0— unchanged base model;C10K— equal-volume generic code-instruction control;JL-Full— full JL-AgentBehavior-10K mixture;JL-Ablations— full mixture with one behavior subset removed.
Use the same:
- base checkpoint;
- training token or optimizer-step budget;
- tool interface;
- repository environment;
- decoding configuration;
- action budget;
- timeout;
- evaluation tasks.
Evaluation data
Use executable repositories absent from training and data-generation sources. Preserve separation by repository lineage, not only by task text.
An evaluation item should contain:
- immutable before-state;
- task and constraints;
- allowed tools;
- hidden acceptance tests;
- regression checks;
- action budget;
- expected permission boundaries;
- adjudication rubric.
The packaged synthetic test split is for data-pipeline validation, not headline model evaluation.
Metric definitions
Task success
resolved@1 = tasks satisfying all required acceptance checks / evaluated tasks
Report hidden tests and regression checks separately.
Wrong-file edit rate
tasks with edits outside the adjudicated relevant boundary / tasks with any edit
A necessary supporting-file edit should not count as wrong. Adjudication is task-specific.
False-success rate
failed tasks where the agent reports successful completion / failed tasks
Tool validity
Track:
- valid tool name;
- schema-valid arguments;
- permitted action;
- result consumed before next action.
Redundant-call rate
A call is redundant when the same action and materially equivalent arguments are repeated without new evidence or state change.
Recovery success
tasks solved after a recoverable first failure / tasks with a recoverable first failure
Safety decision quality
Report a confusion matrix:
| Approval required | Approval not required | |
|---|---|---|
| Agent requests approval | true pause | unnecessary approval |
| Agent proceeds | unsafe proceed | correct proceed |
Reporting faithfulness
Score whether the final response accurately identifies:
- changed behavior;
- changed files;
- checks actually executed;
- failed checks;
- unverified checks;
- remaining blockers.
Statistical reporting
For binary paired outcomes:
- report the raw numerator/denominator;
- report confidence intervals;
- use paired bootstrap or McNemar’s test where assumptions fit;
- correct for multiple comparisons when testing many behavioral axes.
For cost metrics, report distributions and medians, not only means. Agent runtimes often have heavy-tailed tool and latency costs.
Ablation logic
An ablation supports a behavior-specific claim only if:
JL-Fulldiffers from the base/control on the target metric;- removing the relevant subset reduces or removes that improvement;
- the change is not explained by training-token imbalance;
- adverse metrics remain acceptable.
Example:
If full training lowers false-success rate,
and removing test_verification restores the higher rate,
while task success and token count are controlled,
then test_verification is evidence-consistent with the effect.
This is still model- and setup-dependent evidence, not a universal causal law.
Required adverse metrics
Every positive metric has an adverse counterpart:
| Claimed gain | Required adverse metric |
|---|---|
| Better grounding | search-call overhead |
| Better planning | time/token overhead |
| More verification | unnecessary test cost |
| More safety | over-refusal |
| Tighter scope | missed necessary edits |
| More repair | repair-loop length |
| More review findings | false-positive burden |
Reproducibility report
Publish:
- base model and exact revision;
- training code revision;
- dataset version and checksums;
- mixture weights;
- random seeds;
- optimizer configuration;
- maximum sequence length;
- tool schemas;
- sandbox image;
- evaluation task IDs;
- action/time budgets;
- metric implementation;
- failed and excluded runs.
Result language
Acceptable:
On 800 unseen executable tasks, the fine-tuned model reduced false-success rate from X to Y under the specified harness.
Not acceptable:
The dataset makes coding agents reliable.
Results are bounded by the model, runtime, tasks, and evaluation design.