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

Annotations already cover readOnly, idempotent, non-destructive and open-world, so the description doesn't need to re-state safety. It adds genuinely new context: the output is a key that collapses name variations into a single value, and the call costs $0.01 USDC via x402 — cost disclosure is valuable for an agent deciding whether to loop this over records.

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?

Three tight sentences: what it does, how to use the output, what it costs. The core purpose is front-loaded and nothing is redundant.

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?

There is no output schema, but the description explains the return value (a similarity key that is stable across name variations) and how to consume it. For a single-parameter, read-only tool with full annotation coverage, nothing an agent needs in order to call it correctly 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 there is one required parameter, so the baseline is 3. The description adds meaning beyond the schema by showing that reordered and abbreviated forms ('Smith, Robert J.', 'Bob Smith') are acceptable inputs, which the schema's single 'John C. Smith' example 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?

States a specific verb and resource: generates an AI-powered similarity key for an individual's full name for matching/deduplication. The phrase 'similarity key' plus the grouping instruction distinguishes it from score-returning siblings like interzoid_fullname_match_score and from the composite address/company+name matchers.

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 a concrete usage recipe — group records on the returned key to find duplicate contacts and customers across CRM, marketing and customer datasets — which tells the agent exactly when this is the right tool. It stops short of naming the alternative siblings (fullname_match_score, company_and_fullname_match) or stating exclusion cases.

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