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

Annotations already cover read-only and closed-world safety, so the description focuses on what they can't: pagination mechanics (20 per page default, pass next_cursor as cursor) and the fact that total is the full count rather than the page size. This is substantive behavioral context beyond the annotations.

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 tight sentences: what it lists, how filtering works, then pagination. Front-loaded with the primary purpose and no redundant restatement of the tool name or title.

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 still discloses the pagination contract and that total is a global count, which is exactly the information an agent needs to drive the cursor loop correctly. Nothing required to call it 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 50% — brand and category have no schema descriptions at all — and the description compensates by giving brand examples (Lenovo, Dell, HP) and, critically, the semantic caveat that only explicitly classified models match the category enum. That caveat is not derivable from the schema and prevents a common misuse.

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 ("List laptop and Chromebook models covered") plus the catalog scope, which is unmistakably distinct from siblings like search_parts, get_model_parts, and find_repair_guides. An agent can route to this tool 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?

Explains that filtering by brand or category is optional and adds a real selection caveat — "only explicitly classified models match" — which tells the agent when a category filter will silently under-return. No explicit when-not or named alternative, but usage context is clear.

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