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

Annotations already declare readOnly, idempotent and closed-world, so the safety profile is covered. The description adds a genuinely useful operational fact not in the annotations: 'Works without a key', which tells the agent auth is not required. It does not mention rate limits or maximum result size, but the default of 30 newest is carried by the schema.

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, front-loaded with what the tool lists and its returned fields, then search behaviour and downstream routing. No sentence is redundant and nothing is buried at the end.

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?

There is no output schema, but the description compensates by enumerating the returned fields and the default listing size context via the query parameter. Auth requirements and the follow-up tools are both covered, so an agent can call this and act on the result without further inference.

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%, so the baseline is 3; the description earns an extra point by supplying concrete example queries ('bakery', 'Inter') that demonstrate the accepted value space (site name, domain, colour, font) more vividly than the schema's prose. Matching semantics (every word must appear) remain schema-only.

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 ('Lists the brand styles extracted from real websites') and enumerates the returned fields (slug, site name, colours, font), which separates it cleanly from siblings like list_components or list_posts. An agent knows exactly what this tool returns 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?

Explicitly routes the agent downstream: 'Use it to find a slug for get_style, get_component_styled or get_recipe', naming three concrete alternatives. It also explains when to use the query parameter ('for example bakery or Inter'), covering both the default and filtered modes.

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