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

With readOnlyHint=true already declaring the safety profile, the description adds real context: newest-first ordering, the exact attributes returned (status, payment status, amount in cents, refunds, receipt number), and the cursor mechanics. It omits rate limiting or page-size defaults, but the value beyond the annotation is genuine.

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, zero filler, with the resource and ordering front-loaded followed by the pagination recipe and endpoint. Every clause carries information the agent needs.

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 read-only list tool with no output schema, the description enumerates the returned fields and explains pagination, which is enough to call it correctly. Authentication or rate-limit behavior is not covered, but nothing critical 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 coverage is 100%, so limit, status and both cursors are already documented; baseline is 3. The description only adds the one useful recipe of feeding the last id into starting_after, without clarifying ending_before or how status interacts with pagination.

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+resource ('List online payment Checkout Sessions') plus ordering ('newest first') and the fields surfaced, and the GET /checkout/sessions endpoint pins it to the collection. It implicitly separates itself from get/create/expire siblings by being the collection read, but never names them explicitly.

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?

Usage is only implied: 'Cursor pagination: pass starting_after with the last id' tells the agent how to page but never says when to choose this tool over qashier_get_checkout_session or how to filter by status. No when-not-to-use or alternative routing is given.

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