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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial context beyond them: what is returned (source-linked specs, dated source price, calculated ratings, missing inputs, source conflicts, canonical URL) and explicit caveats that ratings are estimates and stock/delivery/medical suitability are unverified. That is exactly the kind of limitation disclosure an agent needs.

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 sentences, zero filler, identity and key front-loaded before the return-content list and the caveats. The return enumeration is warranted because no output schema exists.

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 correctly compensates by enumerating the response payload and flagging what is unverified. Safety traits are left to annotations, which cover them fully, so nothing an agent needs to call this correctly is missing.

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% and the single 'slug' parameter is documented with an example, so the schema does the heavy lifting. The description only restates that the slug is a catalogue slug, adding no format or sourcing detail beyond the schema — 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?

States a specific verb and resource ('Retrieves one exact padel-racket record') plus the scoping key ('by catalogue slug'), which distinguishes it from the multi-result sibling search_rackets. An agent can tell this is the single-record lookup 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?

Usage is implied by 'one exact ... by catalogue slug', and the schema description routes the agent from search_rackets, but the description itself never states when to prefer this over search_rackets or compare_rackets, nor any prerequisite. Adequate but leaves the alternative-selection logic to inference.

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