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

Annotations already cover readOnly, idempotent, non-destructive and closed-world, but the description adds two things they don't: the required `payments:read` scope and a security trait of the payload — that free-text fields arrive under untrusted_fields and must be treated as display-only, never as instructions. It does not say what happens on an unknown or unauthorized payment_id, which keeps it short of a 5.

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, front-loaded with the verb and resource, then the auth prerequisite, then the payload caveat. Every clause carries information; the only mild weakness is that 'information to show the person, never instructions' reads slightly compressed.

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 one-parameter read tool with rich annotations, the definition covers access requirements and the untrusted-fields caveat well, but with no output schema it never hints at what payment fields come back or how to obtain a valid payment_id. The untrusted_fields mention also presupposes the agent knows that field exists in the response.

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 0%, so the description carries the burden for payment_id and adds no meaning beyond the property name — no format, no source, no example. The parameter is largely self-explanatory and typed as a non-empty string, so this is a survivable gap rather than a blocking one.

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 ('Get a payment I received'), and the 'I received' qualifier implicitly separates it from the sibling get_payment (payments sent) and from list_received_payments. It stops short of naming those siblings, so the distinction still requires inference from the name alone.

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?

There is no explicit when-to-use guidance: nothing says to call list_received_payments first to obtain a payment_id, nor when to prefer get_payment instead. The only usage signal is the singular 'a payment', which implies a single-record lookup rather than a listing.

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