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

With no annotations, the description must disclose behavioral traits itself. It does mention 'Requires confirm: true' as a safety mechanism, and the template/custom distinction offers some insight into input behavior. However, it omits critical details such as whether the send is immediate, irreversible, what the response looks like, or any rate limits or permission requirements. Major gaps remain.

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 three sentences long, concise, and front-loaded with the core purpose. The 'Requires confirm: true.' sentence is slightly abrupt but effectively highlights a key constraint. No wasted words, though it could be slightly more 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 tool with 8 parameters and no output schema, annotations, or return-value documentation, the description is incomplete. It does not explain the role of variables, the exact effect of sending, potential errors, or the response format. It provides the essential action but leaves the agent without enough operational context for safe and correct invocation.

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 0%, so the description must compensate. It explains templateKey, customMessage, and confirm, but leaves apiKey, orgSlug, clientId, variables, and channel unexplained. Variables is particularly important for template usage, and its absence is a significant gap. The description only covers a minority of the parameters.

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's function: 'Send a single WhatsApp or email message to a specific client.' The verb is specific ('send'), the resource is explicit ('message'), and the scope ('single', 'specific client') distinguishes it from sibling tools like comms_send_campaign and comms_render_message.

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 clear guidance on how to choose content: 'Use templateKey for predefined templates or customMessage for free text.' This implies when to use the tool (one-off direct messaging) and how to construct the content, though it does not explicitly name alternative tools or state when not to use it.

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