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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower, and the description still adds real context: the signature scheme (Ed25519), the anchoring chain (Merkle proof into a daily root anchored in Bitcoin and Stellar), the terminal outcome states, and that it is free with no key required. It does not describe pagination or response shape, but that is a minor gap given the annotation coverage.

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?

A single dense sentence that front-loads the resource and its distinguishing constraint, then layers in the verification mechanics and prerequisites. Every clause contributes, though the sentence is long and could be split for easier scanning.

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 verification tool taking one opaque nested object with no output schema and 0% param coverage, the description explains what is checked but not the shape of the receipt input or the verification result. The conceptual coverage is good, but the input-format gap leaves an agent under-informed on how to construct the call.

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 'receipt' parameter is a nested object with 0% schema description coverage, so the description carries the burden and only says it is 'one order's PazAIr receipt'. It conveys the semantic association with a single order but gives no expected format, fields, or encoding, leaving the nested-object structure undocumented anywhere.

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?

States a specific verb ('Check/verify') and resource ('one order's PazAIr receipt') and explicitly distinguishes itself from the Word Pass siblings with '(not a Word Pass)'. The clause about Ed25519 signatures, Merkle proof, and order outcome further specifies exactly what is being verified, so an agent can confidently separate it from verify_pass.

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 parenthetical '(not a Word Pass)' acts as an explicit exclusion, steering the agent away from the Word Pass family (verify_pass, check_word_pass, prove_word_pass). 'Free, no key' also communicates the precondition that no auth/key is needed. It stops short of naming the sibling to use instead, so it is clear context rather than full when/when-not routing.

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