draft_message

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

With no annotations, the description carries the safety profile well by emphasizing 'WITHOUT sending it' and explaining that it resolves and echoes the target. It does not mention auth requirements or rate limits, but for a preview-only tool the core behavioral distinction is clear.

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?

Front-loads the preview/no-send behavior, then gives the when-to-use guidance, then compactly documents the three arguments. There is no wasted text.

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 three-parameter preview tool with an output schema, the description covers purpose, safety behavior, usage, and parameter formats. Nothing essential 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 0%, so the description must compensate, and it does: workspace is a configured workspace name, channel accepts an ID or '#general'-style name, and text is Slack mrkdwn. This adds useful format semantics beyond the bare schema.

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?

States a specific action and scope: preview a message without sending it, resolve the channel, and echo the target. It is clearly distinguishable from send_message and other siblings.

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?

Explicitly says to use this tool to review where a message would go before calling send_message. This names both the triggering context and the alternative tool.

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