Send message

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

With no annotations, the description carries the full burden. It discloses the core behavior and the channel-specific delivery nuance, which adds value. However, it does not mention potential side effects, required permissions, or failure scenarios. For a write operation, more behavioral context could be expected.

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 two sentences, front-loaded with the main action, and includes only essential additional context about channel delivery. Every word earns its place, making it highly concise and well-structured.

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 tool with two parameters and no output schema, the description adequately covers the main purpose and the only exception (web vs. external channel). It does not over-explain trivial details, and the lack of an output schema means return values are not required to be described. Slightly more detail on delivery status would improve completeness, but it is generally 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 description coverage is 100%, with both content and conversation_id having descriptive text in the schema. The tool description adds no additional parameter details beyond what the schema already provides, so it meets the baseline but does not enhance understanding.

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 as the agent in an existing conversation.' This is a specific verb+resource combination, and the channel delivery nuance further clarifies its scope. It is distinct from sibling tools like list_conversations or create_lead, which are not messaging tools.

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 implies the tool is used for sending messages in existing conversations, and the external channel condition provides context on when delivery differs. It does not explicitly state when not to use it or mention alternatives, but since no sibling tool overlaps in function, this is adequate.

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