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

Annotations already declare read-only, idempotent, closed-world, non-destructive behavior. The description adds context those fields do not carry: results are cached and stale-ness must be judged via updated timestamps, which is a genuinely useful operational caveat for a data-read tool.

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?

Two short sentences, zero filler, with the core action and the optional filter front-loaded. Every clause 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?

For a simple annotated read tool with no output schema, the description covers the essentials of what it does and how fresh the data is. It nonetheless leaves the status enum and pagination/limit behavior unexplained, which is a real gap given the thin schema coverage.

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 33%: only 'club' is documented, and the description corroborates it as an optional single-club filter. The 'limit' and 'status' parameters receive no explanation in either place, so the description only partially compensates for the coverage gap.

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 ('Read cached public fixtures and results') plus scope ('optionally for one club'). It is clear what the tool returns, but it never names or contrasts with the siblings (fetch, search, get_transfers, list_clubs), so an agent must infer the boundary itself.

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?

'Optionally for one club' implies the filtering use case, and the word 'cached' hints this is not the live-data path, implying 'fetch' for fresh data. However, no explicit when-to-use, when-not, or alternative tool is named, so routing remains inferred.

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