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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing how duplication is determined (same email or key field) and that detection is performed by noCRM's own matching logic rather than a caller-supplied query. It stops short of describing the return shape or result count.

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 short sentences, both front-loaded with the resource definition before the endpoint reference. Nothing is redundant and nothing is padding.

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?

For a single-parameter read tool with full annotation coverage and full schema coverage, the description supplies everything needed to call it correctly. The only gap is what the response looks like (a list of lead records?), which matters slightly more because there is no output schema.

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?

Only one parameter exists and schema coverage is 100%, with the schema documenting lead_id as the noCRM.io lead id. The description's '{id}'/'this lead' wording restates the same meaning without adding format or constraint detail, so the baseline 3 applies.

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 resource and scope — leads that noCRM.io considers possible duplicates of the given lead — and even defines the duplicate criteria (same email or key field). It is easily distinguished from nocrm_get_lead and nocrm_list_leads, though it does not name those siblings explicitly.

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?

Usage is only implied: an agent can infer this is a pre-create check or a dedupe lookup, but the description never says when to call it versus fetching the lead or listing leads. No exclusions or prerequisites are stated.

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