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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description goes beyond them by disclosing the result shape (valid vs. not valid with a reason, plus signer and payload) and the scope of accepted issuers, which is genuinely additive behavioral context.

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?

Two sentences with the outcome front-loaded; little waste. The parenthetical enumerating issuer types ('a house's, a technician's or a shop's') is slightly clunky and could be trimmed without losing meaning.

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 one-parameter verification tool with an output schema and rich annotations, the description covers the operation, the accepted input provenance, and the result semantics. Nothing an agent needs in order to invoke it correctly appears to be missing.

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 100% for the single 'signed' parameter, including the JWS format and size limit, so the schema does the heavy lifting. The description reinforces that the input is a signed form attached to a record but adds nothing about format or constraints beyond 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?

States a specific verb (checks/verifies) and resource (a signed record), plus the outcome: validity, the signer, and the record it holds, or the reason for invalidity. The scope ('from any HandledIQ shop — a house's, a technician's or a shop's') clearly separates it from unrelated siblings like booking_status and get_quote.

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 only implied: you pass a signed form to check it. The note that 'anyone can make the same check with the key at the issuer's id' gives useful context about reproducibility, but there is no explicit when-to-use, when-not-to, or routing against an alternative verification path.

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