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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered structurally. The description adds real behavioral context beyond that: the call is free, requires no key, and returns both current and expired licences, which tells the agent about auth posture and result scope.

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 short sentences, with the content scope front-loaded before the usage hint. Slightly awkward wording ('ask before you trust an agent to buy with you or for you') costs a little, but there is no filler.

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, single-optional-param lookup with full annotation coverage and no output schema, the description supplies the essentials: what is returned, the auth posture, and a reason to call it. Only the sibling disambiguation is 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% and the agent_id field already documents the ag_ prefix and the 'omit it to use your own key' default, so the schema carries the parameter burden. The description adds nothing further about agent_id, making the baseline 3 appropriate.

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 conveys that this returns an agent's licences (current and expired) signed by PazAIr, but the phrasing 'The buyer's licences an agent holds' is grammatically tangled and the verb (fetch/list) is implicit. It does not distinguish itself from the close siblings verify_licence, licence_start, or licence_answer, leaving the agent to infer the boundary.

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?

'ask before you trust an agent to buy with you or for you' gives a situational trigger for calling it, which is more than nothing. However, it never names the alternative (verify_licence) or states when not to use this tool, so routing between the licence-family siblings remains guesswork.

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