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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful semantics beyond that: that these are uncaptured held funds with a seven-day expiry, and which fields (amount, amount_captured, amount_remaining, expired) come back. It does not mention pacing or rate limits, so it is strong rather than exhaustive.

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, zero padding, with the identifying concept and the return fields front-loaded before the endpoint reference. Every clause carries information an agent can use.

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 usefully names the returned fields, and the annotations carry the safety and idempotency profile. For a single-optional-parameter list tool this is nearly sufficient; only the pagination behaviour and the empty-result case are left unstated.

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% and the single page parameter is fully documented in the schema, including the 25-per-page size and the next_page chaining hint. The description adds nothing about pagination, so the baseline 3 for a fully documented schema 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?

Specific verb (List) plus resource (card authorisations), and it defines the concept inline — held funds not yet captured that expire after seven days — which tells an agent exactly what domain object is being enumerated. The List/Get distinction against pinpayments_get_authorisation is evident from the naming, and the endpoint note (GET /authorisations) confirms scope.

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 never states when to reach for this tool over pinpayments_get_authorisation or the other list siblings, and offers no prerequisites or exclusions. The domain gloss on what an authorisation is helps indirectly, but there is no explicit routing guidance for an agent choosing among 34 siblings.

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