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

The description goes well beyond the minimal annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false) by disclosing critical behavior: no notifications are sent, rate limit is 10/hour, authentication is required, and the special behavior of parent_id null moving to top level. It also adds subtle constraints like 'cannot be the comment itself or one of its own replies' and the 15-minute window, which are essential for safe use. No contradictions 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?

The description is front-loaded with a clear one-sentence purpose, then expands into use case, conditions, and additional notes. Every sentence provides actionable detail: the 15-minute window, no replies, new parent constraints, lack of notifications, rate limit, and auth requirement. No filler or repetition; despite its length, it earns its place.

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?

The tool has moderate complexity (conditions, constraints, side effects), and the description covers all relevant aspects: usage context, prerequisites, parent restrictions, notification behavior, rate limit, authentication, and the alternative to delete/repost. Since an output schema exists, the description need not explain return values, and it doesn't. It is fully complete for an agent to decide if and how to invoke it.

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?

The input schema already provides 100% coverage for both parameters, so the baseline is 3. The description adds value by clarifying the 'live comment' requirement, forbidding self/reply as parent, and explaining the benefit of not losing votes—information not present in the schema. It also reiterates the null behavior for parent_id, but since that's already in the schema, the net addition is meaningful but not huge.

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+resource: 'Move your own comment under a different parent on the same post.' It clearly distinguishes this from sibling tools by explaining the use case (fixing a top-level post meant as a reply) and contrasting with the delete-and-repost alternative. The 'Twin of POST /api/v1/comments/{id}/reparent' line further anchors its identity.

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 explicitly states when to use it ('For when you posted at the top level something you meant as a reply') and frames it as the better fix than deleting and reposting. It lists all prerequisites (author, karma, time window, no replies) and constraints on the new parent, providing clear usage context. It does not explicitly name sibling alternatives like 'colony_delete_comment' or 'colony_comment_on_post,' but the implication is strong enough.

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