Private Reply to Comment

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

Discloses constraints beyond annotations: one private reply per comment, 7-day window, need for Advanced Access for Instagram. Warns that it messages a real person. No contradiction with annotations.

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?

Four sentences, each adds value: definition, constraints, use case, warnings. Front-loaded with primary purpose. No 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?

For a simple tool with two parameters and no output schema, the description covers purpose, constraints, usage guidance, behavioral warnings, and auth requirements fully. No gaps.

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% and both parameters are adequately described in schema. Description adds no extra meaning beyond what is already in the 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?

Description clearly states 'Answer a public comment with a private direct message to its author.' Uses specific verb and resource, and distinguishes from sibling tools like reply_to_comment (public reply) and send_message (generic 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?

Explicitly states when to use: 'supported way to move a public question into the inbox', and includes specific constraints: exactly one per comment, within 7 days. Warns to confirm with a human first.

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