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

Beyond the readOnlyHint annotation, the description discloses important scope limitations: it only returns channels/DMs 'the user's brain knows about', includes per-workspace grouping, and indicates what data is returned. This helps set expectations about coverage and output content, though details like pagination or response format aren't mentioned.

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 two sentences with no filler. The first sentence front-loads what the tool returns and its scope, and the second sentence gives an actionable use case. Every part adds value.

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 zero-parameter listing tool with no output schema, the description is complete: it tells the agent the input (nothing), the output scope (known channels/DMs per workspace), the key fields, and the intended purpose. No essential information is missing for correct invocation.

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?

The tool has zero parameters, so the description doesn't need to clarify parameter behavior. The baseline for zero-parameter tools is 4, and the description does enough by explaining what the result contains.

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 a specific verb and resource: lists Slack channels and DMs known to the user, per connected workspace. It also specifies the included fields (ingest status, message count) and distinguishes itself from message-search and posting tools by naming its role in resolving channel names to ids.

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 provides clear usage context: use it to resolve a channel name to its id before searching or posting. It doesn't explicitly name sibling alternatives or state when not to use it, but the instruction is concrete enough for an agent to know when to invoke it.

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