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

No annotations are provided, so the description carries the full burden. It only says it searches messages in accessible channels; it does not disclose return format, pagination, ordering, or whether it searches content vs. metadata. Critical behavioral details are missing.

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, concise sentence with zero filler. It is front-loaded with the action and scope, making it easy to scan. Length is appropriate for the information it conveys.

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?

Given the tool has 3 parameters, no output schema, and no annotations, the description is far too minimal. It does not explain what a 'search' returns, how to combine parameters, or any edge cases. An agent would be left guessing about expected results and behavior.

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 33% (only channelId has a description). The tool description does not explain 'q' or 'limit' at all. With low schema coverage, the description should compensate but does not, leaving the agent to infer parameter meaning from names alone.

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 states the specific action 'Search messages' and a clear scope constraint ('in channels you belong to'). It differentiates from many siblings but does not explicitly distinguish it from 'read_messages', which could also retrieve messages. Still, the verb 'search' implies a query-based behavior that is reasonably distinct.

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 imposes a membership requirement but gives no guidance on when to prefer this over 'read_messages' or any other alternative. There is no explicit 'when not to use' or mention of scenarios where search is appropriate. This is a constraint, not a usage guideline.

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