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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false. The description adds useful behavioral context by stating the search scope and the 50-result cap, though it does not discuss pagination or truncation beyond that cap.

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 short sentences, front-loaded with the search criteria and followed by the result limit. Every phrase adds useful information with no repetition.

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 two-parameter search tool with annotations covering safety, the description provides enough context to call it correctly: searchable fields, exclusion of message text, and result cap. Minor gaps remain around result shape and pagination, but the core invocation context is present.

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 only 50%, and the description compensates by explaining what q matches: contact team name, WhatsApp name, or number. The brand parameter is documented in the schema rather than the description, so the coverage is good but not fully complete.

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 chats) and enumerates the searchable fields: contact team name, WhatsApp name, and number. It also explicitly excludes message text, which distinguishes it from a message-content search.

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?

Makes clear when to use it: searching by contact identity fields, not message text. It does not explicitly name alternatives such as list_chats or read_chat, so the routing guidance is strong but not complete.

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