search_contacts

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

Since no annotations are provided, the description carries the full burden. It discloses important behavioral traits: uses People API searchContacts endpoint, max 30 results, cache warm-up on first use due to lazily populated search index, and required OAuth scope (contacts.readonly). While it doesn't detail edge cases or error behavior, the provided context is substantial and adds value beyond the schema.

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 description is concise (4 sentences) and well-structured: first sentence states purpose, second gives API details, third provides usage guidelines, fourth mentions cache and auth. Every sentence adds value, and the most critical information is 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?

Given the tool's complexity (3 params, no annotations, but an output schema exists), the description covers behavioral traits, usage guidelines, and auth requirements adequately. It does not need to explain return values due to the output schema. The description is complete enough for an agent to decide when and how to use the tool.

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 100% with descriptive parameter descriptions. The tool description does not add significant new meaning to the parameters beyond summarizing the query functionality. However, it adds context like cache warm-up and OAuth scope, which are not parameter-specific. Thus, score is at baseline 3.

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 clearly states the verb 'Search' and the resource 'contacts', specifying the search across names, emails, and phones. It distinguishes from siblings 'list_contacts' (full enumeration) and 'get_contact' (by ID), providing clear 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?

Explicitly instructs when to use alternatives: 'For paginated full enumeration use list_contacts. For a known contact ID use get_contact.' This provides clear when-to-use and when-not-to guidance.

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