post_message

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

With no annotations provided, the description carries full burden. It discloses the prerequisite (requires mail.thread), explains the two message behaviors (comment sent to followers, note is internal), and specifies the return format ({message_id} or {error}). This adds significant behavioral context beyond the input schema.

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 two sentences, front-loading the core purpose and prerequisite, then detailing message types and return value. Every sentence adds necessary information without redundancy.

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 4 parameters, no output schema, and absent annotations, the description provides essential context but omits details on the 'model' parameter (which model/object type) and potential error cases. It is functional but not fully comprehensive for complex usage scenarios.

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 0%. The description only explains the optional 'message_type' parameter (with enum values and their meanings). The required parameters 'body', 'model', and 'record_id' receive no explanation, leaving the agent to infer their purpose.

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 posts a message or internal note on a record, with specific distinction between 'comment' and 'note' message types. It uniquely identifies the resource and action, differentiating it from sibling tools like 'create' or 'update'.

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 mentions the prerequisite 'requires mail.thread' and explains when to use 'comment' vs 'note'. However, it does not provide explicit guidance on when to use this tool over alternatives like 'create' or 'update', nor does it specify 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.