Send a DM

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

Annotations already indicate this is a non-idempotent, open-world mutation. The description adds important policy context beyond annotations: the 24-hour messaging window, the 1000-byte limit, sending 'as the account,' and the instruction to confirm text with the user first.

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 four short, front-loaded sentences. Each sentence adds useful information: the operation, the 24-hour constraint, the recipient_id source, the size limit, and the confirmation step.

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 only two parameters, no output schema, and annotations that already declare mutation behavior, the description covers the critical operational details an agent needs: who can be messaged, how to obtain the recipient ID, the message size limit, and the need for user confirmation.

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%, so the description must compensate. It explains that recipient_id is an Instagram-scoped ID available from ig_list_conversations or ig_get_messages, and it reiterates the 1000-byte limit for text, adding practical meaning beyond the raw schema.

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 opens with a specific verb and resource: 'Send a text DM as the account.' This clearly distinguishes it from sibling tools like ig_reply_to_comment or ig_get_messages.

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?

It gives a critical usage condition (only within 24 hours of the person's last message) and a confirmation requirement. It also points to ig_list_conversations and ig_get_messages for obtaining recipient_id, though it does not explicitly compare against all alternatives.

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