sb3_screenshotCapture the live TurboWarp stage as a base64-encoded PNG to get a real-time visual snapshot of the running Scratch project. Use it to inspect project output during headless playtesting.
Capture the live TurboWarp stage as PNG (base64-wrapped note). (proxied)
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral disclosure burden. It does disclose the return format ('PNG (base64-wrapped note)') and hints at network execution ('proxied'), but it does not state whether a project must be running, what happens on failure, or whether this causes side effects. The description is useful but not richly 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?
The description is a single front-loaded sentence that communicates action, resource, format, and return wrapper without wasted words. The parentheticals add essential detail rather than 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 zero-parameter capture tool with an output schema present, the description is nearly complete: it names the source, format, and encoding. It could mention prerequisites like running project state, but the word 'live' partially covers this and the low complexity keeps the gap small.
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 tool has zero parameters, so the baseline is 4. The description does not need to explain parameter meaning because there is nothing to invoke with; 'live' and output format are the only relevant semantics and they are clearly stated.
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?
'Capture' is a specific verb, the resource is the 'live TurboWarp stage', and the output is narrowly defined as a PNG in a base64-wrapped note. The PNG format immediately distinguishes it from the sibling sb3_screenshot_jpeg even without explicitly naming it.
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 implies the tool is used when a PNG capture of the live stage is needed, but it never explicitly states when to choose this over sb3_screenshot_jpeg or other stage-related tools. There is no when-not or alternative guidance, only an implied use case.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.