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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering safety and side-effect expectations. The description adds valuable behavioral context by listing the data fields returned and emphasizing the dependency on a slug from a prior search, which goes beyond what annotations 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 description is exactly two sentences: the first front-loads the purpose and content, the second gives usage instructions. There is no redundancy or fluff; every word contributes to the agent's understanding.

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 the tool's simplicity (one parameter, output schema present), the description covers purpose, input source, and an example in sufficient detail. It does not need to describe return values since an output schema exists, and it fully supports tool selection and invocation.

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 input schema already documents the slug parameter with an example format, so baseline is 3. The description enhances this by explaining the slug's origin (from search_bikes or get_recent_listings) and providing a conversational use case, adding meaning that the schema does not convey.

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 it retrieves full details for a specific bike listing, enumerating the included fields (specs, condition, frame number presence, photos, delivery, seller's city). It distinguishes itself from listing search tools by requiring a slug from a prior search, making its purpose unambiguous and distinct from siblings like get_recent_listings or search_bikes.

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 explicitly explains when to use the tool: when a user wants more details on a listing, and provides the exact source of the required parameter ('URL slug returned by search_bikes or get_recent_listings'). It includes a concrete conversational example, making the invocation context clear.

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