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

Annotations cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description goes further by enumerating what comes back (sourced specifications, observed price/date, calculated ratings, missing inputs, source conflicts, PadelTrue page) and what the tool cannot do. That capability-boundary disclosure is exactly the value annotations do not carry.

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-loads purpose, then usage, then limits, then citation guidance. Dense but every sentence carries information. The final two sentences about citing racket.page and manufacturer sources are somewhat procedural but genuinely actionable for output handling.

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?

No output schema exists, so the description compensates by enumerating the returned fields and the citation obligations, plus explicit capability limits. An agent has everything needed to call it and present results correctly.

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?

Only one parameter and schema coverage is 100%, with the example slug already in the schema. The description adds modest context by identifying the slug as a catalogue slug sourced from search_rackets, but no format or parsing guidance beyond the schema. Baseline 3 is appropriate.

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+resource ('inspect one exact padel racket by a catalogue slug') and immediately scopes it against siblings by naming the two relevant alternatives and the excluded use case (compare_rackets for two models). An agent can distinguish this from search_rackets and compare_rackets without opening any 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?

Explicit when-to-use ('especially a candidate returned by search_rackets'), explicit when-not ('Use compare_rackets for two known models'), and explicit capability limits ('cannot confirm live stock, shipping or a personal medical outcome'). Nothing is left to inference.

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