scan_for_receipts

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

Discloses offline verification, issuer-agnostic behavior, no API key requirement, and the exact return shape: {found, verified, unverified, all_valid, results}. It also covers the critical no-receipt case, adding value beyond the readOnlyHint and idempotentHint annotations by explaining what the read actually proves.

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?

Three tight sentences front-load the purpose, then give the return structure and the no-receipt edge case. No filler; every sentence adds meaningful information without redundancy.

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 one well-documented parameter and rich annotations, the description covers the output fields and the crucial interpretation of a zero-found result. Since there is no output schema, the description successfully fills that gap.

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?

The single 'message' parameter is already fully described in the input schema with 100% coverage, including accepted types (str/dict/list) and embedded receipts. The tool description reinforces the inbound-message semantics but adds little beyond what the schema already provides.

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 tool's function: 'finds every vcr/1 receipt inside it and verifies each offline' with a specific verb-resource pair and scope ('inbound message'). It also distinguishes itself from the verify_* siblings by framing itself as the 'RECEIVER half' and noting it is 'FREE, no api_key'.

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?

Provides clear when-to-use context: 'When another agent hands you a message' and explains the no-receipt edge case. It does not explicitly name alternatives like verify_receipt for single-receipt verification, so it misses the 'when-not' guidance needed for a 5.

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