Get Duplicate Contact

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

Annotations already declare read-only and idempotent behavior; the description adds conditional search behavior, the endpoint, and the required auth scope contacts.readonly, which is useful context beyond the annotations. No contradiction exists.

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 substantive conditional behavior, endpoint, and scope are compact, but the opening sentence 'Get Duplicate Contact .' simply repeats the title and adds no value. Structure is acceptable but not tightly front-loaded.

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 simple read-only search with fully documented schema and rich annotations, the description supplies the endpoint, search priority, and auth scope needed to invoke it. It does not describe return format, and the global-unique-identifier reference is slightly underspecified, but these are minor gaps for 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?

The schema already documents all three parameters (100% coverage), and the description adds meaningful semantics by defining email and phone priority and tying them to the Allow Duplicate Contact setting. The mapping of the 'global unique identifier' to an actual parameter remains somewhat ambiguous.

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 identifies the resource as duplicate contacts and includes the exact endpoint GET /contacts/search/duplicate, so the tool's purpose is clear. It does not explicitly contrast with sibling tools like contacts_get_contact or contacts_search_contacts_advanced, so it misses full differentiation.

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?

The setting-dependent search priority tells an agent how search keys behave (email then phone when duplicates are allowed, unique identifier otherwise), but it does not state when to prefer this tool over sibling search/get tools. Selection guidance remains mostly implied by the name and endpoint.

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