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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds genuinely non-structured context: 'No usage limit,' which tells the agent there is no quota barrier to calling it repeatedly, plus the grouping/weighting behavior of 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?

Three short sentences with zero padding: purpose, use case, and a constraint. The purpose is front-loaded and every sentence carries information.

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?

There is no output schema, and the description usefully compensates by describing what the return contains (checks, categories, weights, one-line pass descriptions). It omits result size/pagination details, but for a small read-only catalogue this is a minor gap.

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% and the single parameter is an enum-backed optional category filter already fully documented in the schema. The description's phrase 'grouped by category' loosely echoes the parameter but adds no new syntax or filtering semantics, so baseline 3 applies.

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 names a specific resource ('the catalogue of checks the audit runs') and specifies the shape of the output (grouped by category, with weights and a one-line pass description). This makes it clearly distinct from audit_site (which runs the audit) and get_report (which returns results), so an agent can route without opening the schema.

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?

It states two concrete use cases ('explain a score' and 'see what the audit covers'), which gives the agent a clear context for invocation. It does not, however, explicitly name a sibling alternative or a when-not-to-use condition, so it stops short of a 5.

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