compare_runs

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

No annotations are provided, so the description bears full responsibility. It lists comparison metrics but does not disclose side effects, authorization needs, rate limits, or whether it's read-only. The behavioral profile is minimal.

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 a single concise sentence that front-loads the action and lists key comparison points. However, it lacks any structural organization like sections or bullet points, which could improve scanability.

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 the complexity (3 required parameters, 0% schema coverage, no annotations), the description fails to compensate. It does not explain how the diff is presented (despite an output schema existing), and parameter meaning is absent, leaving the agent underinformed.

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?

The input schema has 0% description coverage, and the tool description does not explain any parameter (e.g., what 'project_root' is or that 'run_id_a' and 'run_id_b' must be valid). The parameter semantics are completely absent.

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?

The description clearly states the action ('diff') and the specific aspects compared (duration, turns, tool errors, etc.), and the tool name 'compare_runs' is distinct from siblings like 'list_runs' or 'get_run_report'.

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 implies use for comparing two runs but does not explicitly state when to use or when to avoid, nor does it mention alternatives such as 'get_run_report' for single-run analysis. Usage is inferred rather than guided.

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