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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds substantive operational context beyond that: the two signature algorithms checked, that currency is validated, and that no key or payment is required.

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 action and scope, then appends the precondition. Every clause carries information; nothing is redundant or buried.

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 read-only, closed-world verify tool with full schema coverage and annotations, this is largely complete. The one remaining gap is the outcome on failure — whether an invalid signature yields a boolean result or an error — which is not covered by an output schema.

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?

One parameter with 100% schema description coverage, so the schema already documents the 'licence' object. The description adds only implicit context (an as-issued licence presented by a counterparty) and no format or structure detail, meeting the baseline rather than exceeding it.

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 (verify) and resource (a licence), plus exactly what is being validated: both signatures (Ed25519, ML-DSA-65) and currency. The phrase 'another agent shows you' distinguishes it from the sibling get_licence, which retrieves rather than verifies.

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?

Gives clear triggering context ('a buyer's licence another agent shows you') and states the cost/auth precondition ('Free, no key'). It does not explicitly name a when-not case or point to a sibling alternative, but the use case is unambiguous.

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