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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description usefully reinforces read-only and adds that booking is unavailable here, but says nothing about pagination behavior or how results are ordered, which the schema alone only partly hints at.

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 short sentences, front-loaded with the purpose, then the read-only constraint, then the endpoint. No filler and nothing buried.

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?

For a two-parameter paginated list with no output schema and annotation-covered safety, the description plus schema give an agent enough to invoke correctly; the pagination contract lives in the schema. It could go slightly further by noting what a pickup record contains or any default filters, but nothing essential 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?

Schema description coverage is 100%: page_size and page_number both carry inline documentation including defaults and the instruction to pass the previous reply's next_page. The description adds no parameter meaning beyond that, so the baseline 3 applies.

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 (List) and resource (courier pickups already booked for the account), and scopes it to existing bookings rather than creation. No sibling lists pickups, so no differentiation is required, and the added 'GET /api/pickup' pins the exact operation.

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?

'Read only; booking a pickup is not available here' explicitly marks the boundary of when not to expect write behavior, which steers the agent away from a nonexistent booking tool. It stops short of naming an alternative tool or the conditions under which this list is the right choice (e.g., date filtering does not exist here).

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