slack_send_message

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only mentions 'requires approval', which hints at a mutation gate, but does not explain effects such as the message being visible to channel members, irreversibility, or required permissions. For a mutation tool sending external messages, this is insufficient.

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, front-loaded sentence with no unnecessary words. 'Send a message to a Slack channel (requires approval)' is concise and to the point.

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 simple send-message tool, the description is minimally adequate. However, it omits the thread_ts parameter's behavior, any details about the approval workflow, and what happens after sending. With no annotations or output schema, more context would help an agent, but this is acceptable for a basic tool.

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%, as each parameter (text, channel, thread_ts) has a description. The tool description adds no additional parameter semantics beyond what the schema already provides, so the baseline of 3 applies.

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 states 'Send a message to a Slack channel (requires approval)', which is a specific verb and resource. It clearly identifies the action but does not differentiate from the sibling tool slack_send_thread_reply, which also sends a message (in a thread). Lacks explicit sibling distinction.

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?

No guidance is provided on when to use this tool versus alternatives. The sibling slack_send_thread_reply exists for thread messages, but the description does not mention it or offer any context. The '(requires approval)' note is a constraint, not a usage guideline.

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