Retrieve a transfer by your reference

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

Annotations already cover read-only, idempotent, non-destructive semantics, and the description adds real value beyond them: references are unique per mode, and an unknown reference yields `404 resource_missing`. It does not describe the returned object, but no output schema exists and the error contract is the more useful disclosure.

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 sentences, front-loaded with the action, then the safety rationale and error behavior. Nothing is repeated and nothing is superfluous.

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 single-parameter read tool with full annotation coverage and no output schema, the description covers purpose, selection rationale, and failure behavior. Only the shape of a successful response is left implicit, which is acceptable here.

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 coverage is 100% and the single parameter is already documented. The description adds one meaningful nuance, that uniqueness is scoped per mode, but no format or length constraints beyond that. Baseline 3 is appropriate.

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 gives a specific verb and resource ('Retrieve a transfer') and immediately narrows the lookup key to 'the reference you gave when sending it', which cleanly separates it from the id-based get_transfer sibling without naming it.

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 states a concrete situation for use: checking a transfer after a timeout when you never received its id. There is no explicit when-not or named alternative (get_transfer), but the scenario described is enough to route an agent correctly.

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