send_channel_message

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

Without annotations, the description fully bears the burden of behavioral disclosure. It explains the side effect (everyone in channel sees it), the failure mode (non-employee members cause refusal, no post), and the irreversibility (deleting the message does not help). This is comprehensive for a simple mutation tool.

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 well-structured with a brief opening, key warnings in separate sentences, and an Args section. Slightly verbose in the middle paragraph, but each sentence adds clear value. Could potentially trim the middle block slightly, but overall efficient.

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 simple input schema (2 string params), no annotations, but an output schema present (which can describe return values), the description covers all critical behavior: side effects, prerequisites, error conditions, and parameter semantics. Nothing essential 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?

The schema has 0% description coverage, so the description must compensate entirely. It explains that `channel_id` must come from `list_message_targets`, and `message` accepts plain text or simple HTML. This adds crucial meaning beyond the bare property names 'channel_id' and 'message'.

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 the tool posts to an existing Discuss channel, distinguishes it from creating a channel, and indicates the audience. The verb 'post' and resource 'existing Discuss channel' are specific and 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?

Explicitly tells the agent not to use this to create channels, directs to `list_message_targets` for valid channel IDs, and warns about unrecoverability of wrong-sized room posts. It also references sibling `notify_user` for external follower rules, providing clear when-to-use and when-not-to-use guidance.

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