search_messages

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

With no annotations, the description carries the burden of disclosure. It explicitly mentions the 500-message scan limit, which is a key behavioral trait not otherwise captured. The rest of the behavior (returning matches) is implied by 'search,' and the read-only nature is obvious from the context.

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 a single, front-loaded sentence with zero filler. It efficiently conveys the essential purpose and a key limitation.

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 search tool with 3 well-described parameters and no output schema, the description is largely complete. It identifies the channel, keyword, and scan depth. It doesn't describe the return format, but that's not critical for a search tool where matching messages are expected.

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 100%, so the baseline is 3. The description adds meaningful context by revealing that the search is limited to 500 recent messages, a behavioral constraint not present in the parameter descriptions. This supplements the limit parameter's semantics.

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 for messages containing a keyword within a channel, using a specific verb ('search') and resource ('messages'). It also includes a scope limitation ('up to 500 recent messages') that distinguishes it from sibling tools like get_messages.

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 conveys clear context: use this when you need to find messages by keyword in a channel. It doesn't explicitly mention alternatives or exclusions, but the purpose is obvious enough to differentiate from listing messages. The 500-message scan limit also implies a constraint on usage.

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