send_message

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

Since no annotations are provided, the description carries full behavioral burden. It discloses that the tool only stages, requires confirm_send to post, returns a draft_id and other fields, drafts expire in 1 hour and can only be confirmed once. This fully communicates the behavioral traits.

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 five sentences, each adding distinct value: staging behavior, return values, expiry, thread usage, and alternative tool. No redundant or irrelevant information. Front-loaded with the key action.

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 tool has 4 parameters, an output schema, and no annotations, the description covers the staging workflow, return values, thread usage, and expiration. It doesn't handle error cases (e.g., invalid channel) or permission requirements, but the completeness is high for the stated purpose. The output schema provides return value details, so the description doesn't need to replicate that.

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. It explains thread_ts is for thread replies and suggests using send_reply_quote for quotes. However, it does not explain workspace (though return mentions 'resolved workspace') or provide details on text and channel, which are somewhat self-explanatory but could be clarified. Partial value added.

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 starts with 'Stage a message send. Does NOT post until confirm_send is called.' This clearly states the action (stage a send) and the resource (message), distinguishing it from sibling tools like confirm_send. It also differentiates from send_reply_quote for quote replies.

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 provides explicit guidance for thread replies (set thread_ts) and redirects to send_reply_quote for quote replies. It implies the two-phase workflow (stage then confirm), but doesn't explicitly state when not to use this tool (e.g., for quick sends without staging). However, the context is clear enough for an agent.

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