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

Beyond the read-only, idempotent, non-destructive annotations, the description adds meaningful behavioral context: access is limited to groups you are in, several cases return 404, and a personal token is required. This gives the agent important preconditions and failure behavior.

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 compact and front-loaded: purpose first, then usage, access constraints, error behavior, and auth. Each sentence contributes useful information without unnecessary wording.

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 read tool with rich annotations and full schema coverage, the description covers purpose, use case, access limits, 404 cases, and authentication. The main remaining gap is that it does not describe the returned message content, though the output is strongly implied by the tool name.

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 description coverage is 100%, so group_id and message_id are already fully documented in the schema. The description adds slight context by linking message_id to a reply's reply_to field, but does not otherwise explain parameter meaning beyond 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 gives a specific verb and resource: read one group chat message. It is broadly distinguishable from group-write siblings like send_group_message, but it does not explicitly contrast with the similarly named get_message, leaving the sibling boundary implicit.

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?

It provides a clear use case: fetching the message referenced by a reply's reply_to field. It does not name alternatives or exclusions, such as when to use get_message instead, but the intended context is clear.

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