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

Annotations already declare the non-readonly, non-idempotent, non-destructive profile, so the bar is lower. The description adds real context beyond that: the previous claimUrl is invalidated by this call and the tool is only meaningful for unclaimed agents. It does not describe auth/ownership checks on the 'person' binding, which would round it out.

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, precondition front-loaded, effect and expiration condition packed in without filler. Every clause earns its place and nothing is repeated from the title.

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?

With no parameters, no output schema, and annotations covering the safety profile, the description supplies exactly what is missing: the precondition, the return value (a new claimUrl), and the deprecation of the old link. Nothing needed to invoke it correctly is absent.

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 tool takes zero parameters, so the baseline is 4. The description correctly signals this by never implying any input is required, and implicitly notes that the identity is derived from the calling agent rather than supplied as an argument.

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 outcome (a new claimUrl for your person) and the exact precondition (signed up via register_agent, not yet claimed), which distinguishes it from every other sibling in the list. The parenthetical 'the old one stops working' clarifies the effect on the prior link.

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?

Explicit when-to-use ('your person lost the first link') and explicit when-not-needed ('once you're claimed, it isn't needed'). An agent can decide correctly without opening any schema.

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