send_message

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

No annotations are provided, so the description must cover behavioral traits. It mentions the tier requirement but does not specify what happens on success/failure, if there are rate limits, or how the message is delivered (e.g., async confirmation). This lack of detail reduces transparency for an operation that modifies state.

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?

Two sentences with no wasted words: the first sentence states the main purpose, the second adds a crucial prerequisite. Information is front-loaded and 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?

For a simple 1-parameter tool with no output schema, the description covers the purpose and a key prerequisite. It lacks detail on return values or error handling, but given the tool's low complexity, it is mostly complete.

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 is 100% with a single 'message' parameter described as 'Message to send to the Run402 developers'. The description adds no additional semantics beyond the schema, so baseline 3 is appropriate.

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 verb 'Send' and specific resource 'message to the Run402 developers'. It distinguishes from sibling tools like 'send_email' which sends emails to arbitrary addresses, indicating a dedicated contact channel.

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 explicitly notes a prerequisite 'Requires an active tier', providing clear context for when the tool can be used. No explicit when-not or alternative guidance is needed given the tool's simplicity and unique purpose.

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