search_messages

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

No annotations provided, so the description carries the full burden. It discloses auth requirements, error behavior (loud error with auth_type), and the channel sugar mechanism. It does not cover pagination or rate limits, but some behavioral context is present.

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 and well-structured, using bullet-like formatting for query modifiers. Every sentence adds value, and there is no redundancy or fluff.

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 6 parameters, 0% schema coverage, no annotations, but an output schema exists, the description covers the most critical parts (query and channel) and auth. It omits details on limit, sort, sort_dir, and workspace, leaving the agent to infer or rely on the output schema.

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 0%, so the description must compensate. It explains the `query` parameter with Slack modifiers and the `channel` parameter as sugar. However, parameters like `sort`, `limit`, `sort_dir`, and `workspace` are not described, leaving gaps.

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 identifies the tool as searching messages with Slack's full-text search. It explains the query syntax and distinguishes from sibling tools like search_channels via explicit channel usage guidance.

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 states when to use and provides critical auth context (requires xoxc/xoxp, not xoxb). It does not explicitly list when not to use alternatives, but the context is sufficient for decision making.

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