Screenshot a scene

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

With readOnlyHint/destructiveHint=false already covering the safety profile, the description adds real operational context the annotations do not: Movie Maker mode, a game window briefly appearing, and the image being written to a temp folder. That window/side-effect disclosure is exactly the extra context an agent needs, though it doesn't say how long capture can block or whether the run is torn down afterward.

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 sentences with no filler; the core action and its purpose are front-loaded, with mechanism and side effects trailing. Every clause 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?

With no output schema, the description carries the return-value burden and does say it returns the rendered screenshot plus a temp-folder copy. It stops short of saying in what form the image is returned (inline image vs. file path), which is the one thing an agent might still need to know.

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 schema already documents scene, seconds, resolution and projectPath with defaults and bounds. The description only loosely echoes two of them ("or one scene", "for a moment") without adding syntax or format detail beyond the schema, so the baseline 3 applies.

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?

"Run the game (or one scene) for a moment and return a screenshot of what it renders" gives a specific verb (run/capture) and resource (screenshot of rendered scene), and the Movie Maker mechanism makes the behavior concrete. It is clearly distinct in function from run_project, but it never names that sibling, so the differentiation is implicit rather than explicit.

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?

"So you can see the result of your changes" implies the use case (visual verification after edits) but states no explicit when-to-use rule, no exclusions, and no pointer to run_project as the non-capturing alternative. Usage is inferable but not spelled out.

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