compare_test_runs

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must convey behavioral traits. It discloses the comparison logic and default behavior but does not clarify whether the tool is read-only, what authentication is needed, or any rate limits. The output format is also not described.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is exceptionally concise with two sentences that convey core functionality and a key behavioral detail. Every word is meaningful, no fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no output schema, the description partially explains output ('Shows new failures, fixed tests, and persistent failures') but lacks details on format or structure. For a moderate-complexity tool comparing runs, this is adequate but leaves room for improvement.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, providing baseline at 3. The description reiterates the default behavior for base_run_id, which is already in the schema description, adding no new semantic information beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the tool compares test failures between two runs to identify regressions, specifying the types of results (new failures, fixed tests, persistent failures). While the verb 'compare' is specific and the resource is clear, it does not explicitly differentiate itself from sibling tools like get_failed_tests or get_run_tests, which could also relate to test failures.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains when to use the tool (to identify regressions by comparing runs) and provides a default behavior when base_run_id is omitted. However, it does not specify when not to use the tool or mention alternative tools for similar tasks.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.