slack_list_channels

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

With no annotations, the description must disclose behavior. It states that it returns a list of channels with pagination metadata and explains the cursor parameter for pagination. This goes beyond the schema by describing the return structure. It does not mention rate limits, authentication, or any side effects, but as a read-only listing tool, the disclosure is adequate. A 4 reflects that it adds meaningful behavioral context beyond the schema.

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, well-structured with 'Args' and 'Returns' sections. Each parameter is listed with its meaning and default, and the return type is stated. There is no fluff; every sentence adds value. It is front-loaded with the main action.

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 complexity (pagination, multiple parameters), the description is complete. It covers all parameters, defaults, and return format. The presence of an output schema further reduces the need to describe return values in detail. There is nothing an agent needs to call it correctly that is missing.

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 all four parameters: types (comma-separated channel types), exclude_archived (default true), limit (range 1-1000, default 200), and cursor (pagination cursor). This adds significant meaning beyond the bare schema, including defaults, ranges, and formats. This is exemplary parameter documentation.

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 begins with 'List channels in the Slack workspace,' which is a specific verb-resource pair. It clearly distinguishes from sibling tools like slack_list_channel_members (which lists members of a channel) and slack_get_channel_info (which gets details of one channel). The purpose is unambiguous.

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 implies usage: it lists channels, and the parameters allow filtering by type and archived status. However, it does not explicitly state when to use this versus alternatives like slack_search_messages. The context is clear, but no exclusions or alternative tool mentions are provided. A 4 is appropriate because the intended usage is evident without being explicitly contrasted.

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