Get chat metadata (subject, members, mute state)

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

Annotations already indicate readOnlyHint and idempotentHint, and the description adds valuable behavioral context: the WhatsApp Desktop DB is a sync cache, older metadata may be missing locally, and user-authored content should not be treated as instructions. It also discloses the shape differences between group and 1:1 chats.

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 front-loaded with the core action and then provides useful detail about group vs 1:1 shapes and data-cache caveats. The final sentence about message bodies is slightly tangential for a metadata tool and could be mistaken as implying message bodies are returned, though it does serve a security purpose.

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?

With an output schema present, the description need not explain return values. It covers what metadata is returned, how 1:1 chats differ, local data limitations, and safety expectations. It could be more complete by pointing users toward list_chats for discovering chat_id, but the tool is simple enough that this is a minor gap.

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 schema has only chat_id and zero description coverage, so the description's 'by chat_id' confirms which parameter to use, but it adds little beyond the parameter name and type. It doesn't explain how chat_id is obtained or whether there are special formatting concerns. For a single self-explanatory integer parameter, this is adequate but not deeply informative.

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 opens with a specific verb and resource: 'Returns metadata for one chat by chat_id.' It then differentiates group metadata from 1:1 chat metadata, clarifying exactly what kind of information the agent should expect. This is sufficiently distinct from sibling tools like list_chats or read_chat.

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 clearly establishes that this tool is for a single chat's metadata, not for listing chats or reading message content. It does not explicitly name alternatives or say 'use X instead of Y,' but the scope is clear enough that an agent can infer when to select it.

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