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

The annotations cover the safety profile (readOnly, idempotent, non-destructive), but the description adds state-specific behavior the annotations cannot convey: a pending receipt yields retryAfterSeconds with a recovery delay, and a refunded receipt means service credits return to the account. These outcomes materially change what the caller does next.

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?

Four dense sentences, front-loaded with the operation's identity before the constraints and recovery path. Every sentence carries distinct information (identity, exclusions, pending behavior, refund behavior) with no filler.

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?

An output schema exists, so return values need not be spelled out, and the description still covers the essential non-obvious states (pending, refunded) and the recovery route. For a single-parameter, idempotent read tool this is complete.

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 operationId schema description already documents persistence and reuse, so the baseline is 3. The description adds marginal value by tying operationId to the recovery action ('using the same authenticated agent connection and operationId'), contextualizing it within the retry flow rather than merely restating the schema.

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 states a specific verb and resource ('Read the original purchase-1 receipt') and immediately scopes it by naming the exact identifier used ('operationId'). It actively distinguishes itself from the sibling purchase_appraisal by declaring 'cannot create a purchase,' so an agent can separate reading from buying without opening either schema.

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 gives explicit negative guidance ('does not start or resume delivery and cannot create a purchase') and a concrete alternative path for the pending case ('recover with purchase_appraisal using the SAME operationId and original arguments'). Both when-not-to-use and when-to-use-an-alternative are covered, leaving nothing to inference.

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