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

Annotations already declare readOnlyHint=false, idempotentHint=true, openWorldHint=true and destructiveHint=false. The description adds value beyond those flags: the ordered fallback chain for verification and the side effect that a newly verified product gets a free check while remaining private until a drive. It is consistent with the annotations.

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?

It is compact and front-loads the key framing ("Step 2 of 3"). Sentences are dense with parentheticals but every clause conveys behavioral or routing information, so little is wasted.

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 output schema, the description carries the burden of explaining mechanics, and it does so well (both verification paths, ordering, side effects, privacy). It stops short of describing what a success/failure response looks like or auth prerequisites, but overall it is nearly complete for an agent to call it correctly.

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 coverage is 100%, so the baseline would be 3. The description adds real meaning by explaining what the code parameter does when supplied (checks the mailed code) and what happens in its absence (DNS TXT → meta → file), which the schema does not convey.

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 states a specific verb+resource ("verifies a claim") and frames it in a workflow ("Step 2 of 3"). It distinguishes the two paths (with code vs. without) and names the sibling send_claim_code as the source of the code. The only weakness is that steps 1 and 3 of the workflow are left unnamed.

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?

It clearly separates the two invocation modes: with a code, use the mailed 6-digit code; without, fall back to DNS TXT, then meta tag, then file. It also gives the business context ("Every order but the free check needs a verified claim") that motivates use. It does not name when NOT to use it or an explicit alternative tool.

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