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

Annotations already indicate read-only and non-destructive behavior. The description adds the 'local cache fallback' detail, which is useful context beyond the annotations, but it does not explain when the fallback triggers, how stale cached data might be, or any other behavioral implications.

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 front-loaded sentence with no filler. It names the action and resource first and adds only the cache-fallback detail, which is the one meaningful behavioral qualifier.

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?

The schema covers parameters and annotations cover the safety profile, but there is no output schema and the cache fallback is left under-specified. The tool would be easier to invoke correctly if it explained when fallback data is used and what the response contains. Still, for a simple read-only list call, the definition is minimally adequate.

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?

All four parameters (page, params, status, pageSize) have descriptions in the schema, so the description does not need to restate them. The description itself adds no additional parameter meaning, such as how status filtering works or how 'params' interacts with typed fields.

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 ('List') and a specific resource ('checkout sessions from the Pay API'). It clearly separates listing from the sibling peer_checkout_show, but it does not explicitly contrast with other list tools or describe when a checkout session is the right resource.

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?

No guidance is given about when to use this tool instead of peer_checkout_show or any sibling list tool. There are no exclusions, alternatives, or conditions such as 'use this when you need all checkout sessions' or 'use show for a single session.'

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