Private reply (DM) to commenter

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

Annotations already declare destructiveHint=true and readOnlyHint=false. The description adds the time window constraint but no additional behavioral traits beyond confirming the write nature. Minor added value.

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 a single, front-loaded sentence that conveys the essential action and a key constraint. Every word is necessary and no extraneous content.

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 existence of an output schema and sibling tools, the description is sufficient to differentiate this tool. It mentions the platform (Instagram) and a critical temporal constraint. However, it could mention prerequisites like a valid comment ID or user existence for full completeness.

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?

With 40% schema description coverage, several parameters (user, commentId, message) lack schema descriptions. The tool description does not explain these parameters, leaving the agent to infer meaning from parameter names alone. The description adds no parameter-level detail.

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'), the resource ('private DM to comment author'), and includes a critical constraint ('within Instagram's 7-day reply window'). It distinguishes from sibling tool 'public_reply_to_comment' by specifying 'private DM'.

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 implies when to use: to send a private reply to a comment author, contrasting with public replies. It mentions the 7-day window, which is a usage condition. However, it does not explicitly exclude other platforms or provide alternative scenarios.

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