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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds real value by disclosing what data each record type contains (a stand-in for the absent output schema), but says nothing about not-found behavior, errors, or whether the record is cached/live.

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 core purpose in the first clause, then a compact per-category field list. The enumeration is long but justified given the absence of an output schema; no filler sentences.

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 one-parameter read tool with no output schema, the description does exactly the needed extra work: it describes the shape of what comes back for each catalogue category. Only failure/empty-result behavior is unaddressed, which 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 coverage is 100% and there is only one parameter, so the schema already carries the load. The description still adds meaning by tying the slug to its origin — the /catalogue/{slug} path segment in the collectorists.com address — which clarifies the expected format beyond the plain 'string' in the schema.

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 precise verb and resource — the facts and description of ONE published catalogue record, keyed by slug — and enumerates the returned fields per category (coins, LEGO sets, Magic cards, Funko Pop!). The singular 'one record ... by the slug' distinguishes it from a list/search tool, though no sibling is named explicitly.

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: retrieve a single record once you have its slug. There is no explicit when-to-use/when-not statement and no named alternative (e.g., search_catalogue is only referenced in the schema, not the description). An agent can infer the workflow but is not told it.

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