send_message

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the basic action ('send') without mentioning permissions, side effects, failure modes, delivery guarantees, or response behavior. For a mutation tool with no annotation support, this is insufficient.

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, concise sentence that directly states the tool's purpose. It is front-loaded and contains no filler or redundant details, earning full marks for conciseness.

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 tool with 9 parameters, no output schema, and no annotations, the description lacks critical context. It does not explain how parameters interact per channel (e.g., subject needed for email), scheduling behavior, or expected response. The schema covers parameters, but the overall description leaves notable gaps in usage context.

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 schema provides 100% description coverage for all 9 parameters, including types, enum values, and field-specific notes (e.g., 'subject required for Email type'). The description adds little beyond reiterating message types (SMS, Email, WhatsApp) which are already in the schema, so it does not compensate beyond the baseline.

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 tool sends a message to a contact and lists examples of channels (SMS, Email, WhatsApp, etc.), using a specific verb and resource. This distinguishes it from sibling tools that manage conversations, tasks, or calendars, none of which are message-sending 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 but provides no explicit when-to-use or when-not-to-use guidance. It does not mention alternatives or exclusions, though there are no obvious sibling tools with overlapping functionality, so the implied usage is generally clear.

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