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

No annotations are provided, so the description carries the full burden, and it does disclose real behavioral traits: the resolution is attributed to the caller and is reversible, and resolved:false flips the direction. It omits permission/auth requirements and any side effects on notifications, so it is strong but not exhaustive.

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?

Two tightly written sentences with the primary action front-loaded, followed by the inverse operation and its behavioral caveats. Zero filler.

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 mutation tool with an output schema (so return values need no explanation), the description covers purpose, both operating modes, reversibility, and attribution. The main remaining gap is access/auth context, which the token parameter only partially addresses in the schema.

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 50%, and the description adds meaning beyond the schema by explaining that resolved:false performs a reopen, whereas the schema only notes 'Defaults to true.' It is silent on designId/threadId, but those names are self-explanatory and the token param is described 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?

The description states a specific verb and resource ('Close a comment thread') and adds the inverse operation ('reopen one by passing resolved: false'), so the agent knows exactly what state change is performed. It does not explicitly contrast with similar siblings like ui_builder_acknowledge_comment or ui_builder_react_to_comment, so it stops short of a 5.

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 clear trigger condition – close once the thread 'is answered' – and explains the alternative mode for reopening. There is no explicit when-not guidance or naming of competing tools (e.g., acknowledge vs resolve), which keeps it below 5.

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