search_contactsLocate WhatsApp contacts and groups by searching a name fragment or phone number. Use this to quickly find the right person or group for messaging.
Find people or groups by name or phone number.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| query | Yes | Name fragment or phone digits |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavior on its own. It conveys a read-style search operation but does not mention that it is non-mutating, what matching rules apply, whether results include groups only or also users, or how limit affects results.
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, front-loaded sentence communicates the core operation and search criteria with no filler or repetition. Every word 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 simple read-only search with two parameters, the description reaches a minimum viable level: an agent can identify the purpose and construct a query. However, with no output schema and no mention of result shape, matching behavior, or limit semantics, it leaves several non-obvious details to inference.
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?
The description adds little beyond the schema for the query parameter and does not explain the limit parameter at all. With schema coverage at 50%, one parameter's semantics are only inferable from its name and numeric constraints.
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 a specific verb ('Find') and names the resource clearly: people or groups, searched by name or phone number. This distinguishes it from siblings like search_messages and other contact-adjacent tools.
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 the tool is for looking up contacts or groups by name or phone, but it does not explicitly state when to prefer it over alternatives such as search_messages or list_chats. There is no when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.