get_region_metrics_tool

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It indicates a computation but does not state whether any side effects occur, what prerequisites exist (e.g., commitSha must reference a valid commit), or what the return value contains. This is insufficient for safe and correct invocation.

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, front-loaded sentence that conveys the primary action without unnecessary words. It earns a 4 rather than 5 because it omits important details, but it is appropriately concise and structured.

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?

With no output schema and no annotations, the description must explain the tool's context fully, but it does not. It fails to describe what 'PID-like metrics' means, what the return value contains, or how the parameters affect the computation. The description is a minimal viable statement but leaves significant gaps for an agent.

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 description coverage is 0%, and the description only implies 'project' and 'region' without explaining them. The required commitSha parameter is not mentioned at all, and the relationship between parameters is unclear. The description fails to compensate for the schema's lack of detail, leaving the agent to guess parameter meanings.

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 states 'Compute PID-like metrics and mutation score for a specific region within a project,' using a specific verb and naming the resource and scope. It distinguishes from siblings like run_mutation_tests_tool by focusing on computing metrics rather than executing tests. However, 'PID-like metrics' is jargon that is not defined, which slightly blurs the purpose.

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 offers no guidance on when to use this tool versus alternatives. It does not mention that it is a read-only computation, nor does it exclude cases where running mutation tests would be more appropriate. This lack of contextual guidance leaves the agent to infer usage from the tool name alone.

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