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

Annotations already declare readOnlyHint=true, destructiveHint=false and a closed world, so safety is covered. The description adds non-obvious behavioral context: the result is a full evidence review with provenance (URLs plus retrieval dates) and it explicitly states 'No numeric score', which warns the agent not to expect a rating field.

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?

Front-loaded with the action and resource, then a compact enumeration of the return payload. The middle sentence about filtered searches is slightly oblique but earns its place by preventing confusion with search results. No filler.

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, the description carries the return-value burden, and it does so by listing the substantive fields including provenance data. It could go slightly further on error behavior for an unknown slug, but for a single-record read-only getter the essentials are covered.

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% with both parameters documented, so the baseline is 3. The description reinforces that 'slug' selects exactly one agency, but it adds nothing about the optional user_request parameter or slug formatting beyond what the schema already 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?

States a specific verb and resource ('Return the full evidence review for one agency slug') and enumerates the payload: rank or unranked standing, services, sourced facts with URLs and retrieval dates, profile and contact URLs. The clause 'A filtered search can show a different position' implicitly separates it from the plural search_agencies sibling, so an agent can route correctly without opening a 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?

The description gives clear context for when this record is the right one to read: a single canonical agency lookup whose position may differ from a filtered search result. It stops short of naming search_agencies or stating an explicit exclusion, so the agent must infer the alternative rather than being told.

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