icloud-mcp

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

Without annotations, the description carries the burden of disclosure and successfully specifies return fields (names, phones, emails) compensating for the missing output schema. However, it omits explicit safety declarations (read-only nature) or pagination behavior details.

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 sentences with zero waste: first establishes scope and source (iCloud Contacts), second discloses return payload structure. Every element 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?

For a 2-parameter tool with no output schema, the description adequately covers the data returned and source system. Could be improved by noting this retrieves all contacts (subject to pagination) versus filtered results, but sufficient for correct 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?

With 100% schema description coverage for both parameters (limit and offset), the schema fully documents the pagination interface. The description adds no supplemental parameter semantics, meeting the baseline for high-coverage schemas.

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 specific verb 'List' with resource 'contacts from iCloud Contacts', clearly distinguishing it from sibling tools like get_contact (singular retrieval), search_contacts (filtered query), and mutation tools like create_contact/delete_contact.

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 implied by the verb 'List' suggesting bulk enumeration versus siblings like 'search' or 'get', but provides no explicit guidance on when to prefer this over search_contacts or whether it returns all contacts versus a default subset.

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