search_messages

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

The description mentions it is cheaper and provides count limits, but lacks details on sorting, case sensitivity, or returned fields. Since annotations are absent, a more thorough disclosure is needed.

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 concise with two introductory sentences and a clear args list. Every sentence is valuable, and key information is front-loaded.

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?

The description covers all input parameters and provides usage context. The existence of an output schema likely covers return values, so the input is well-documented. Could mention prerequisites like room existence.

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?

Each parameter is described with additional meaning beyond the schema: room_id can be ID or name, query is keyword(s), count has default and max. This fully covers all three parameters.

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 clearly states the tool searches messages by keyword, and it distinguishes itself from the sibling tool get_channel_messages by noting it is much cheaper for specific searches.

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 explicitly contrasts with get_channel_messages, providing context on when to use this tool. However, it does not mention other siblings or when not to use.

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