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. 'Send a message to a Slack channel' states the basic effect but does not mention whether it sends as the bot or user by default, required scopes like chat:write, message visibility, or other side effects such as surfacing in channel history. It is not misleading, but it is thin.

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 filler or redundancy. Every word adds clarity to the core operation. It is concise in structure, even if it is thin on contextual detail.

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 six parameters, no annotations, no output schema, and a large sibling set, this description is incomplete. It does not help the agent decide between send_message and reply_in_thread or send_ephemeral, nor does it describe expected response behavior or authorization requirements. The schema covers parameters, but the overall context for correct invocation 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 100%, so the schema already documents all six parameters. The description adds no parameter-level meaning beyond identifying that the destination is a Slack channel, which is the baseline expectation for this tool.

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 says 'Send a message to a Slack channel,' which clearly identifies the verb (send), resource (message), and destination (Slack channel). However, it does not distinguish this tool from closely related siblings such as reply_in_thread, send_ephemeral, or schedule_message.

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?

There is no guidance about when to use send_message versus alternatives. With many sibling tools like reply_in_thread, send_ephemeral, and update_message, the agent is left to guess which one fits the user's intent. No exclusions or contextual cues are provided.

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