Apple Find Duplicate Contacts

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so no side-effect disclosure is needed. The description adds that results are 'likely' duplicates, indicating heuristic rather than exact matching, and frames the tool as a pre-action disambiguation step. It does not disclose output shape or the distinction between all duplicates and merge candidates.

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?

One front-loaded sentence states action, resource, and purpose with no filler. Every clause earns its place.

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?

The tool is simple with no required parameters and has an output schema, but because schema description coverage is 0%, the description must clarify parameters and the difference between querying and merge candidates. It does not, leaving an agent uncertain about invocation options.

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 0%, and the description mentiones none of the two parameters. 'query' and 'merge_candidates_only' remain unexplained; the description adds no meaning beyond the bare property names and defaults.

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?

Clearly states a specific action (find likely duplicate contacts) and resource (Apple Contacts) plus intended purpose (disambiguate people before acting). It does not explicitly contrast with sibling tools like contacts_search_contacts or apple_prepare_unique_contact, so it misses a 5.

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 phrase 'so assistants can disambiguate people before acting' implies a natural trigger: run before acting on a person when duplicates may exist. It provides contextual timing but no explicit when-not or alternative routing, such as when to use contacts_search_contacts or apple_prepare_unique_contact.

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