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

Annotations already signal read-only/non-destructive behavior, and the description reinforces this with 'never merges records'. The security warning about CRM field values being untrusted user content adds valuable context beyond the annotations, though match criteria and result details remain undisclosed.

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?

The description is compact: two sentences plus a security warning. The core action is front-loaded, and every sentence adds functional or safety-relevant meaning.

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?

Given low parameter documentation and no output schema, the description leaves significant gaps: it does not explain what fields are matched, how results are ranked, what 'visible' means, or what the response will contain. It is adequate for intent but insufficient for reliable invocation.

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 only 14%, and the tool description does not explain any of the seven parameters. The agent is left to infer how email, firstName, lastName, companyId, excludeId, and limit interact for duplicate matching.

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 uses a specific verb ('Find'), names the resource ('contact duplicates'), and states the intended use phase ('before creating a contact'). It also explicitly disclaims merging, which distinguishes it from mutation-oriented sibling tools.

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 frames when to use the tool: before creating a contact, and directs the agent to review ambiguous matches rather than auto-resolving them. It does not explicitly name a sibling alternative, but the 'never merges records' statement provides a meaningful exclusion.

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