search_contactsFind contacts by name, email, or phone. A phone number matches however it is typed: "(864) 555-1234", "864-555-1234" and "+18645551234" all find the same contact.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max rows, default 25, ceiling 100 | |
| query | Yes | A name fragment, email address, or phone number. Needs at least two real characters — a one-character search matches most of the account and is refused. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, destructiveHint false and openWorldHint false, so the safety profile is covered. The description adds genuinely non-obvious behavioral detail: phone matching is format-insensitive across '(864) 555-1234', '864-555-1234' and '+18645551234', which an agent could not derive from structured fields.
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, zero filler, with the core purpose front-loaded and the clarifying example immediately after. Every sentence carries information an agent needs.
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 two-parameter read-only search with no output schema, the definition covers purpose and matching behavior well. It does not state what a result set looks like or how multiple partial matches are ordered, a minor gap given the absent output schema.
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 baseline is 3, but the description earns an upgrade by explaining matching semantics for the query parameter — that a phone number matches regardless of formatting — which the schema text does not state. The limit parameter is only covered by the schema (default 25, ceiling 100), not the description.
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?
States a specific verb and resource ('Find contacts') plus the searchable attributes, which cleanly separates it from create/update/delete siblings in intent. It never names list_contacts or get_contact, so the boundary between searching, listing, and fetching a single record is left to inference.
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 implies search-by-fragment usage but gives no explicit when-to-use or when-not-to-use guidance, and no sibling alternative is named. An agent has to guess whether list_contacts or get_contact is the better call when it already has an exact identifier.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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