messages_create

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

With no annotations provided, the description carries full burden but only states 'Create a new message' without disclosing behavioral traits. It doesn't mention permissions needed, whether this is a write operation (implied but not explicit), response format, error conditions, or any side effects, leaving significant gaps.

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 with a single sentence 'Create a new message', which is front-loaded and wastes no words. However, this brevity comes at the cost of completeness, but purely on conciseness, it's optimal.

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 complexity of a creation tool with nested objects, no annotations, and no output schema, the description is inadequate. It fails to explain what a 'message' is, how creation works, what the response contains, or any behavioral details, making it incomplete for effective use.

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%, so the schema documents the single 'message' parameter as an object with id, text, tokens, etc. The description adds no additional meaning beyond 'Create a new message', which merely restates the tool's purpose without elaborating on parameter usage or constraints.

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 'Create a new message' states the basic action and resource (message), but it's vague about what a 'message' entails in this context. It doesn't distinguish from sibling tools like messages_update or messages_trigger, leaving ambiguity about the specific type of creation operation.

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 guidance is provided on when to use this tool versus alternatives like messages_update or messages_trigger. The description lacks context about prerequisites, timing, or any exclusions, offering no help in tool selection.

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