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

Annotations already cover the read-only and non-destructive nature. The description adds useful behavioral context: 'live guide counts' signals dynamic counts rather than static values, and 'machine-readable data rather than prose' indicates the response format. This goes beyond what annotations alone provide.

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 entire description is one sentence with the core purpose front-loaded and the supporting details following. Every word contributes meaning—there is no filler or repetition.

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 parameters and an output schema present, the description fully specifies what the tool returns. It lists all major vocabulary components and even notes the live guide counts. Nothing an agent needs to call 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, so the schema provides no semantics to augment. The description correctly focuses on the response content rather than parameters. A baseline of 4 is appropriate for a parameterless 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 verb 'Get' and the resource 'bicycle.guide vocabulary', then enumerates the specific contents (domains, shelves, series, personas, guide_types, conventions). This makes it easily distinguishable from sibling tools like get_guide or list_guides, which target different resources.

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 phrase 'as machine-readable data rather than prose' implies when to use this tool, but it does not explicitly name alternatives or state when not to use it. The usage context is clear for a no-parameter read-only listing tool, yet exclusion guidance is absent.

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