coverage_summary

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

The description adds no behavioral context beyond the annotations. Annotations already communicate read-only, idempotent, and non-destructive behavior, but the description does not explain what the summary contains, how counts are aggregated, or how the optional filters affect the result.

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?

'Coverage Summary' is technically short, but it is under-specification rather than efficient communication. There is no useful content to front-load, so the structure provides no assistance to an agent.

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?

Despite having annotations and an output schema, the description does not clarify what the tool computes, when it should be selected, or how it relates to coverage_tutors and coverage_gaps. An agent browsing the sibling list would be unable to confidently choose this tool over similar coverage-related tools.

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 100%, so the input schema already explains both parameters: subject restricts counts, and postcode relates to tutor reach. The description itself adds no parameter information, but the high schema coverage makes this acceptable at baseline.

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 'Coverage Summary' is a direct restatement of the tool name and provides no verb or specific resource. It does not distinguish coverage_summary from related siblings like coverage_tutors or coverage_gaps.

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 gives no guidance on when to use this tool, when not to use it, or what alternatives might be more appropriate. Sibling tools such as coverage_tutors and coverage_gaps are not mentioned, leaving the agent to guess the intended use case.

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