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

Annotations only give the generic write/destructive/open-world profile; the description adds the material specifics: the reply is published publicly and immediately under the channel's identity, it cannot be undone from here, there is a 2,000-character ceiling, and the call is refused (with an explanatory message) when the channel connection is broken or the plan doesn't include replies.

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?

Purpose, visibility, irreversibility and eligibility are front-loaded and every sentence carries information. The public/immediate posting and irreversibility points are stated twice in slightly different words, which is minor padding.

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?

With an output schema present, return values need no explanation, and the description covers the remaining agent-relevant context: public posting, irreversibility, length cap, and both refusal paths (broken connection, plan restriction). Nothing needed to call it correctly is missing.

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 baseline is 3. The description restates the 2,000-character limit that the schema's maxLength already encodes and says nothing about postId, commentId, postPlatformId, or the rootCommentId used for threaded replies.

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?

States a specific verb (reply) and resource (a comment on one of the workspace's published posts), and scopes it away from conversation replies and comment moderation, which are handled by siblings like reply_to_conversation and moderate_comment.

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?

Ends with an explicit trigger: 'Use this when the user wants to answer a comment on one of their published posts,' plus concrete eligibility conditions (all plans except Free; connection must be live). It does not name an alternative tool or state when not to use it, so it stops short of a 5.

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