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

Annotations mark this as a non-read-only, non-destructive, non-idempotent write. The description adds real value beyond them by disclosing the issuer credential requirement (argument or Bearer header), scoping the mutation with "Never revokes," and explaining that replacement is via supersedes rather than overwrite. It stops short of describing what happens on duplicate issuance or failure, but the key behavioral traits are covered.

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?

It opens with the core action and the critical auth caveat, but degenerates into a long semicolon-chained list that is hard to parse. Information is dense and mostly earns its place, though the run-on structure hurts readability.

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 14-parameter, 11-required mutation tool with an output schema (so return values needn't be explained), the description covers authentication and the most consequential fields. However, several required parameters remain semantically opaque, leaving an agent to guess at values for a write operation, which is a meaningful 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?

With 0% schema description coverage, the description carries the full burden. It defines the crucial parameters well (subject = barcode, result = verified/listed/stale/unknown, the four readings, supersedes) but leaves several others (verified_at, market, core_version, profile_version, answer_hash, match_hash) as bare names with no added meaning.

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 opens with a specific verb+resource: "Issue one receipt," and bounds the operation with "Never revokes," so an agent can tell it creates rather than removes records. It does not name any of the siblings (verify_receipt, list_receipts, get_statement) to explicitly route between them, but the action and scope are unambiguous.

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?

Usage is implied rather than stated: the credential requirement and the supersedes mechanism tell the agent what preconditions and replacement scenarios look like, and "Never revokes" rules out a revocation use case. There is no explicit when-to-use-vs-sibling guidance (e.g., vs verify_receipt), which keeps this at minimum-viable.

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