Skip frames

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

With no annotations, the description carries full burden. It discloses frame-accurate vs wall-clock, pausing, returning a screenshot, and the fast-forward threshold above ~180 frames. It stops short of describing all possible side effects, but is adequate for a simple operation.

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?

Three concise sentences, all carrying essential information. No redundancy or 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 single-parameter tool with no output schema, it explains purpose, return value, and performance behavior. It does not cover error conditions or boundary edge cases, but those are not critical for the core use case.

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%, so baseline is 3, but the description adds 'core-internal frames (frame-accurate, not wall-clock),' clarifying count meaning beyond the schema. The fast-forward threshold also provides practical context for choosing a count.

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 clearly states the tool advances the emulator by exactly N core-internal frames, a specific verb+resource with unique scope. It also notes that it returns a screenshot, distinguishing it from sibling tools like get_current_screen.

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 suggests 'Use this to let held inputs or animations play out,' giving concrete use cases. It does not mention alternatives or exclusions, but the context is clear enough for tool selection.

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