upservice_send_channel_message

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

Annotations already indicate readOnlyHint=false. The description adds that it returns a JSON of the created message but does not disclose behavioral traits like idempotency implications (though schema mentions message_id for idempotency), auth needs, or side effects. No contradiction with annotations.

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 concise with a clear front-loaded purpose sentence. The args listing could be streamlined but is efficient. No wasted words.

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 moderate complexity (one parameter object with nested properties) and rich schema descriptions, the description is adequate but lacks guidance on prerequisites (e.g., obtaining channel UUID) and error scenarios. The output schema likely covers return structure, so the return description is sufficient.

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 of parameter descriptions is high (all parameters have descriptions), so baseline is 3. The description lists parameter names but adds no meaning beyond the schema, which already includes detailed explanations for content and mentions.

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 it creates a new message in a channel, not in a chat room, distinguishing it from the sibling tool upservice_send_chat_message. The verb 'create' and resource 'message in 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?

The description implicitly distinguishes channel vs chat room but does not explicitly state when to use this tool over alternatives like upservice_send_chat_message. It provides no prerequisites or exclusions, so usage guidance is minimal.

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