Slack Search Messages

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

readOnlyHint=true already tells the agent this is a non-mutating search, so the annotation carries the safety profile. The description adds the Slack query-language capability, which is real behavioral context, but says nothing about result caps, permission scope (which channels are searchable), or pagination limits.

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?

Two sentences, zero filler, with the core action front-loaded and the operator syntax immediately after. Nothing is repeated from the schema or annotations.

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?

An output schema exists and parameters are fully documented, so the description needn't explain return values. It is nearly complete for a search tool, but omitting what is actually searchable (DMs? private channels? user token scope) leaves one meaningful gap for an agent deciding whether results will be authoritative.

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 all five parameters are self-documenting and the baseline would be 3. The description earns above baseline by explaining that the vague "query" field accepts Slack search modifiers with concrete examples (from:, in:, has:link, before:/after:/during:), which the schema does not convey.

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?

States a specific verb and resource: "Search messages in the Slack workspace," which is distinct from history/thread siblings that retrieve by channel or thread. The workspace-wide scope is a useful differentiator, though it never names a sibling explicitly.

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 modifier list implies the tool is for cross-workspace keyword lookup rather than per-channel retrieval, so an agent can infer when to use it over slack_get_channel_history. However, there is no explicit "use this when / use X instead" routing and no prerequisites stated.

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