facets_catalog

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

With no annotations, the description carries the full burden. It discloses that the data is fetched once (caching behavior), requires no login, and details the exact structure of each entry (scope, kind, label/description, bundle default, constraint). This goes well beyond a generic 'list facets' statement.

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?

Two sentences, front-loaded with the core purpose ('full list of facets'), followed by a dense but efficient description of entry fields. No filler; every clause contributes value.

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?

Despite lacking an output schema, the description comprehensively explains what each entry contains and how it should be used. It also covers auth ('No login required') and cache semantics ('fetched ONCE'), making it complete for a zero-param tool.

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?

The tool has zero parameters and an empty schema, so the baseline is 4. The description correctly focuses on the output structure instead of parameters, which is appropriate for a no-argument catalog tool.

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?

The description clearly states the tool retrieves 'the full list of facets HyperRoute ranks tools on,' serving as a reference for filling `facets` on `recommend` and `set_preferences`. This distinguishes it from siblings by framing it as a static catalog rather than an action-oriented tool.

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?

It explicitly says 'fetched ONCE — reference for filling facets on recommend and for choosing what to persist with set_preferences,' giving clear use cases. It doesn't state when not to use it, but the context is strong. The 'No login required' note adds practical usage guidance.

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