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

Annotations already declare readOnlyHint=true, but the description adds genuinely useful context beyond them: the endpoint is POST /payments/search, and it explicitly flags that a POST here is a READ that does not mutate. That preempts a real misreading. It still says nothing about result caps, cursor lifecycle, or rate limits.

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 verb+resource and the read-only note. The final sentence largely repeats what the schema already documents, so it is slightly redundant but not wasteful.

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 output schema, the description should carry at least a hint of the response shape and cursor reuse, and it does not. The nested, open-ended filter objects (additionalProperties) also imply flexible semantics that are never described, though annotations cover the safety profile.

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%, so limit, query, and pagination are already documented with examples ({ reference, id, status, currency, amount, from, to } and { after, before }). The description only restates that query and paging fields are accepted, adding no syntax or constraint detail beyond the schema; 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 and resource ('Search payments') plus the underlying endpoint (POST /payments/search), so the agent knows exactly what operation this is. It does not explicitly distinguish itself from the closest sibling, checkout_list_payments, leaving the search-vs-list choice to inference.

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?

It says to pass a query filter object and/or paging fields, which is parameter guidance rather than usage guidance. There is no statement of when to prefer this over checkout_list_payments or checkout_get_payment, and no exclusions or prerequisites.

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