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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), yet the description still adds real value: it explains result semantics (same key = similar company AND similar person) and discloses a concrete cost ($0.01 USDC via x402). It stops short of stating determinism, key format, or whether a similarity score is included.

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: the mechanism, then the match semantics, with cost appended last. Front-loaded and no filler anywhere.

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?

No output schema exists, and the description compensates by explaining what the returned key means. It leaves minor ambiguity about the return shape (bare key string vs. key plus score) and normalization expectations for input names, but the essentials for calling it correctly are present.

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 earns a bump by clarifying that the two inputs are fused into a single key rather than scored independently — a distinction the schema alone cannot convey and one that changes how an agent interprets the call.

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?

Names a specific verb and resource: generates one combined similarity key from company + full name for contact deduplication. The word 'combined' distinguishes it from the single-field siblings interzoid_fullname_match and interzoid_company_match_advanced without needing to open any schema.

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 usage context ('contact-level matching in CRM, sales, and marketing datasets'), which is better than nothing, but never says when to prefer this over the many adjacent siblings (interzoid_company_and_address_match, interzoid_fullname_match, interzoid_company_match_advanced). The agent must infer the choice boundary itself.

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