get_payin_by_id

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

With no annotations provided, the description carries the full burden. It conveys a read-only operation via 'Retrieve details', which is safe, but it does not disclose behavior for not-found errors or the exact response structure. For a simple get-by-id this is adequate but has clear gaps.

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 compact sentence with a short title ('Get Payin'), a fuller explanation, and the endpoint reference. Every part earns its place; no wasteful words.

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, single-resource lookup, the description sufficiently indicates the purpose and usage. The absence of an output schema makes return details vague ('details'), but the low complexity and clear name make this acceptable.

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%: the 'id' parameter is described as 'Unique identifier of the Payin'. The description's 'by its unique identifier' adds no new meaning beyond the schema, so the baseline of 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?

The description clearly states the action 'Retrieve details of a specific Payin by its unique identifier' and names the resource (Payin), distinguishing it from siblings like get_payins (list) and get_payout_by_id (different resource). The endpoint [GET /payins/{id}] reinforces the specific single-resource purpose.

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?

The description implies use when you need a single Payin by ID, contrasting with get_payins for lists. However, it does not explicitly name alternatives or state when not to use it, so it falls short of a 5.

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