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

Annotations already mark this as read-only, non-destructive, and closed-world. The description adds useful behavioral context beyond the annotations: it returns machine-readable data rather than prose, includes live guide counts, and covers classification conventions. This helps set expectations about the response's nature.

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?

The description is a single, information-dense sentence with the main object front-loaded ('Get the bicycle.guide vocabulary'). The em-dash list efficiently enumerates all delivered elements without redundancy or unnecessary words.

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?

Given zero parameters, read-only annotations, and an output schema, the description is complete. It tells the agent what categories of data are returned, notes that counts are live, and clarifies that the data is machine-readable. Nothing essential for invoking this tool 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?

The tool has zero parameters and the schema already covers 100% of them, so there is no parameter documentation burden for the description to carry. The baseline for a zero-parameter tool is 4, and the description appropriately focuses on output content rather than params.

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 states a specific verb ('Get') and resource ('the bicycle.guide vocabulary') and enumerates exactly what is included: domains, shelves with guide counts, series, personas, guide_types, and classification conventions. This clearly distinguishes it from sibling tools like list_guides or get_guide, which would return guide content rather than taxonomy.

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?

The description implies the tool should be used when an agent needs taxonomy/vocabulary data as machine-readable input rather than prose, but it does not explicitly state when not to use it or name alternatives. There is no direct comparison to siblings such as list_guides or list_capabilities.

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