slack_channel_history

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

No annotations are provided, so the description carries full burden. It discloses the read-only nature and that it returns recent messages, but lacks details on response format, pagination behavior, rate limits, or what 'recent' means. The schema covers parameters, but the description adds no extra behavioral 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, efficient sentence with an immediate follow-up instruction. It is front-loaded with the core purpose and presents the key usage tip without any superfluous words.

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's simplicity (5 parameters, 1 required, no output schema, no annotations), the description covers the essential usage context. It could mention result ordering or pagination, but the sibling list provides additional context, making it sufficient for an agent to use correctly.

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 100%, so the baseline is 3. The description adds value by clarifying the channel parameter must be an ID (not a name) and referencing slack_list_channels for resolution, but does not elaborate on other parameters beyond what the schema already provides.

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's action ('Read recent messages') and resource ('from a Slack channel'), and notes it is read-only. It distinguishes itself from siblings by specifying that channel IDs (not names) are required and instructing to resolve names via slack_list_channels first.

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 advises to use slack_list_channels first to resolve channel names to IDs, providing clear prerequisite context. It implies the tool is for reading only, but does not explicitly list when not to use it or mention alternatives like slack_search_messages or slack_thread_replies.

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