Send a message

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, but the description adds important behavioral context: the message is visible immediately and posts as the user. This goes beyond the annotations by clarifying the side effects (permanent, attributed, immediate) and implies a need for caution. 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 a single, well-constructed sentence that front-loads the core purpose and appends a necessary caution. Every word earns its place; there is no fluff or redundancy.

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's simplicity—four parameters, two required, no output schema—the description covers the essential behavior: it sends a message that is immediately visible and attributed. It does not mention return values, but those are not required for correct invocation. It could be improved by naming siblings for differentiation, but that falls under usage guidelines.

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 input schema has 100% description coverage for all four parameters, so the schema already fully documents them. The description adds nothing about parameter meaning beyond what the schema provides, so it earns the baseline of 3.

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 action: 'Send a message to a chat.' It specifies the resource (a chat message) and the verb (send), and adds the key distinction that it posts as the caller, separating it from forwarding or file-sending siblings. The immediate visibility note further sharpens what this tool does.

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 gives a clear context—send when you need to deliver a message that is immediately visible and attributed to the user—but it does not explicitly mention alternatives like send_file or forward, nor does it state when not to use it. The warning 'only send what was actually asked for' is a usage guideline but not a routing guide to other tools.

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