create_a_new_message

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

Description adds behavioral context beyond annotations: explicitly states 'creates data', 'Not idempotent — calling twice may create duplicates', and mentions HTTP method. Aligns with annotations (readOnlyHint=false, idempotentHint=false). No contradictions.

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?

Description is highly concise: header with purpose and path, then a brief sentence on behavior. No redundant information, and key details are front-loaded.

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 full schema coverage and annotations, the description sufficiently covers purpose, behavior, and idempotency. Omits output details, but no output schema exists, so this is acceptable. Slightly higher than baseline due to completeness within its scope.

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 detailed parameter descriptions (e.g., required fields: fromname, email, reply2). Description does not add additional parameter meaning beyond what the schema provides, so baseline score of 3 applies.

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?

Description clearly states 'Create a message' and includes the HTTP endpoint 'POST /messages'. It specifies the resource (message) and action (create), distinguishing it from sibling tools like update_a_message or delete_a_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?

No explicit guidance on when to use this tool versus alternatives. Lacks prerequisites, exclusions, or recommended context for use. The non-idempotence note is a behavioral warning but not a usage guideline.

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