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

With no annotations, the description carries the full burden. It helpfully discloses that the tool does not charge or sign for the wallet and that the returned message must be signed with EIP-191, but it omits auth requirements, challenge expiry length, idempotency, and whether the challenge is stored server-side.

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?

The description is three efficient sentences with the core action front-loaded. The caveat about not charging or signing is useful and earns its place, though a bit more structural clarity around the workflow could help.

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 tool with no annotations, no output schema, and three required parameters, the description is only partially complete. It covers the signing requirement and return-message behavior but leaves operationId unexplained and the relationship to submit_delivery_receipt implicit.

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 0%, so the description should compensate. It gives some meaning to 'payer' (wallet that signs) and 'verdict' (accepted or disputed), but does not explain 'operationId' at all, leaving a required parameter undocumented.

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 uses a specific verb and resource: 'Create a short-lived challenge'. It clarifies the domain action (payer wallet signs accepted/disputed for a retained result) but does not explicitly distinguish this tool from sibling tools such as submit_delivery_receipt or read_assigned_delivery_receipts.

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 by the workflow: create a challenge, then sign the returned message with EIP-191. However, the description does not state when to call this versus submit_delivery_receipt or other sibling tools, nor does it name alternatives or exclusions.

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