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

Annotations already declare readOnlyHint=true, so the safety profile is covered by structured data. Beyond that the description adds only 'in full', which hints the complete payment record is returned rather than a summary — useful but thin, with no mention of error behavior for a missing/invalid id.

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 short fragments, zero filler, with the scope statement front-loaded. The telegraphic style borders on under-specification rather than verbosity, but nothing is wasted.

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 readOnlyHint and a fully documented schema, most contract information is present. It is only adequate, however: nothing is said about what a payment record contains or how not-found cases surface, and there is no output schema to cover the return shape.

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?

There is a single parameter and schema description coverage is 100%, with the schema documenting 'Payment id' plus positivity and integer constraints. The description adds no format or sourcing detail beyond the schema, 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 the resource (one payment) and scope ('in full'), and the endpoint reference GET /payments/{id} confirms a single-record retrieval. That implicitly distinguishes it from splose_list_payments, but it never names the sibling or states the verb outright, so it falls short of a 5.

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 on when to use this versus splose_list_payments or splose_get_invoice, and no mention of prerequisites (e.g. needing a payment_id from a list call). The agent must infer usage from the name alone.

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