list-trend-categories

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

With no annotations provided, the description carries the full burden and does reasonably well: it discloses the backing wrapper and the GET endpoint, which implies a read-only, side-effect-free operation, and it describes the returned structure. It omits auth/rate-limit considerations and error behavior, which keeps it from a 5.

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 the purpose in the first sentence, then layers backend and return details. The wrapper name and the GET path are near-duplicates of the same fact, a small redundancy that keeps it from a 5.

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 zero-parameter read tool with no output schema, the description supplies exactly what is otherwise missing: the return shape and a warning that the display label is `title`, not the deprecated `name`. An agent has everything needed to call it and read the result.

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?

Zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-param tool applies. The response-shape note is genuinely additive but belongs to return values rather than parameters.

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 top-level feed categories used by the home feed'), which clearly separates it from list-trend-tags and other list-* siblings by naming the resource and scope. It stops short of explicitly pointing at the sibling alternative, so it is clear but not fully differentiated.

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 only implied via the phrase 'used by the home feed', giving context but not a when-to-use rule, prerequisites, or exclusions. Nothing tells the agent when to prefer this over list-trend-tags.

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