capture_screenshot

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

With no annotations provided, the description carries the behavioral burden and does a solid job: it discloses that the tool runs a scene, captures and returns an image, requires a non-headless display, and suggests xvfb-run for headless environments. It does not mention process lifecycle side effects or interactions with an already-running Godot instance, but the core behavioral expectations are transparent.

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 sentences with no wasted words: the first states the action and result, the second explains why the agent would use it, and the third gives a crucial environment caveat. The most important information is front-loaded.

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 description is complete enough for a single-purpose capture tool: it states what it returns, why it matters, and the environment requirement. There is no output schema, so the description's note that it 'returns the image' is valuable. It could add a bit more about behavior when Godot is already running or about the returned image format, but those are secondary gaps.

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 has 100% description coverage for all four parameters, including defaults and timeout behavior. The description adds no parameter-specific detail beyond what the schema provides, so the baseline score of 3 is appropriate.

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 action ('run a Godot scene and capture a screenshot') and the resource ('rendered output'), and it explains the purpose: letting the agent visually verify the scene. It does not differentiate itself from the nearly identical sibling tool 'capture_scene_screenshot', so it loses the fifth point.

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 gives useful context for when this tool is appropriate: when visual verification of a rendered scene is needed. It also provides an important operational prerequisite (real display required, xvfb-run for headless Linux). It does not explicitly name alternatives or state when not to use it, so it does not reach a 5.

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