scratchjr_screenshot

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

Annotations indicate readOnlyHint=true, so no contradiction; the description adds value by clarifying that this captures the actual window and saves a file whose path is returned. It does not disclose details like window focus behavior or failure states, but for a non-mutating capture tool this is reasonably 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 focused sentence that front-loads the action and purpose. Every phrase earns its place, with no redundant or vague wording.

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, the description adequately states input (none), what it does, and what it returns (image and file path). It does not mention prerequisites such as the app being open, but this is inferable from sibling tools and does not undermine correct invocation.

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?

There are zero parameters, so the schema carries no burden. The baseline of 4 is appropriate because the description does not need to clarify any parameter details.

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 identifies a specific action ('Capture the real ScratchJr window'), a clear resource, and a concrete purpose ('for visual verification'). It also states the return value (image and saved file path), making it easy to distinguish from siblings like status or get_project.

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 when to use this tool ('for visual verification') but does not explicitly state when to prefer it over alternatives or mention prerequisites such as needing the ScratchJr app to be running/connected. Usage guidance is present but only implied.

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