Apple Prepare Unique Contact

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

With annotations already marking the tool readOnly and idempotent, the description adds a meaningful behavioral branch: it can return duplicate groups instead of a resolved contact. No contradiction with annotations; 'resolve' and 'return' fit readOnly behavior.

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?

A single sentence that front-loads the main purpose and then adds the important duplicate behavior. No filler or repetition of schema/annotation information.

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 one-parameter tool with an output schema and safety annotations, the description covers the main purpose and the key branching behavior. The main missing context is query semantics, already penalized under parameter semantics.

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 0% and the description does not compensate: the single 'query' parameter is never explained in terms of accepted format (name, email, phone, partial match). The agent is left to infer that query somehow identifies a contact.

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 action ('resolve a contact') and resource (contact), plus a condition for stopping when duplicates need cleanup. It is clear but does not explicitly distinguish itself from sibling tools such as apple_find_duplicate_contacts or contacts_resolve_message_recipient.

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 gives clear context: use for a person-targeted workflow before acting, and stop if duplicates are found. It does not name alternatives or exclusions, so it stops a point short of the top score.

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