ncloud_datastream_send_message

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

With no annotations, the description must carry the burden of behavioral disclosure. It indicates a write operation ('send') but omits details about side effects, return values, error behavior, or rate limits. The credential note is a partial disclosure, but insufficient overall.

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 extremely concise—one sentence plus a brief note—with no wasted words. It is front-loaded with the action and efficiently communicates the key requirement.

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 has 4 parameters, no output schema, and no annotations, the description is too minimal. It lacks context about the return value, error handling, or how this tool fits into the Data Stream workflow. The credential note is useful but insufficient for complete understanding.

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%, so the input schema already describes all parameters. The description does not add additional semantic meaning beyond what the schema provides, meeting the baseline for high coverage.

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 the resource 'message to a Data Stream topic', providing a clear purpose. It uses a specific verb+resource structure and distinguishes from sibling datastream tools (like list or create topics) by describing a distinct action.

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 includes a critical usage guideline: 'Requires Sub Account credentials (main account keys are not allowed for this API).' However, it does not provide guidance on when to use this tool versus alternatives, nor does it exclude any specific scenarios.

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