search_contacts

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals the return structure ({items, count, hasMore}) and the pagination contract, which is valuable. It also implies that items contain contact IDs (by referencing "a matching ID") without exposing full details. While it doesn't mention rate limits or exceptions, the core behaviors are transparently disclosed for a search tool.

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 exceptionally concise: two sentences that cover functionality, return structure, pagination behavior, and an alternative. There is no redundancy or filler. Each sentence earns its place, 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?

Without an output schema, the description adequately explains the return format and pagination. It also provides a next-step action (call get_contact). It does not specify the exact structure of items beyond implying IDs, nor does it cover potential errors or edge cases, but given the tool's simplicity (three parameters, no nested objects), it is reasonably complete for an agent to invoke and interpret results.

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%, so the schema already documents each parameter in detail. The description adds semantic value beyond the schema by explaining how limit and offset work together in a pagination loop ("increment offset by limit when hasMore is true"), which is not explicitly stated in the parameter descriptions. It also clarifies that query is matched against contact names, aligning with the schema.

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 tool's function: "Search contacts by matching the query against contact names." This specifies the verb (search), resource (contacts), and matching mechanism (against names), distinguishing it from sibling tools like list_contacts (which likely lists all contacts without a query) and get_contact (which fetches full details). It also explicitly points to get_contact for full details, further clarifying its scope.

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 description provides actionable usage guidance: it explains the pagination pattern with "increment offset by limit when hasMore is true" and directs users to get_contact for full details, serving as an alternative. It does not explicitly enumerate when not to use this tool versus listing contacts, but the contrast with get_contact is clear. The guidance is practical and context-specific.

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