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

The description says the tool 'Apply[s]' a timeout and equates it with the HUD timer running out, implying a state-changing operation, while annotations set readOnlyHint=true. This is an annotation contradiction, and the description does not clarify side effects or state impact beyond the conflicting hint.

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?

One concise, front-loaded sentence with a useful parenthetical analogy. Every word contributes to the intended behavior without unnecessary 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?

For a state-triggering action, the description is thin: it does not explain the consequences of applying the timeout, whether the run ends, or how this relates to the choice workflow. The output schema may cover return shape, but the behavioral impact and relationship to siblings remain underspecified.

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 only parameter, runId, is fully documented in the input schema (100% coverage), so the description does not need to repeat it. The description adds no additional parameter meaning beyond the schema, meeting the baseline.

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 uses a specific verb ('Apply') and resource ('Last Frame choice timeout') and clarifies with an analogy to the play HUD timer running out. It is reasonably distinct from siblings like choose_last_frame, though it does not explicitly differentiate itself.

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?

Usage is implied: use when the Last Frame choice timeout should be applied, equivalent to the HUD timer expiring. However, there is no explicit guidance about when to prefer this over choose_last_frame or related Last Frame actions, so routing is left to inference.

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