vnc_screenshot

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

Annotations are absent, so the description must disclose behavioral traits. It does not mention how the screenshot is returned (file path, base64), whether default is full-screen, or how format/quality/region affect output; it only restates the obvious action.

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 maximally concise, but it is under-specified rather than appropriately sized. For a tool with four parameters and no output schema, a single sentence without operational details is not enough.

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?

Given the moderate complexity of the input schema, the absence of output schema and annotations, the description is far from complete. It fails to explain return values, default capture behavior, or how region/format parameters work.

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 only 25% (overlay), and the description adds no parameter semantics. It does not explain region coordinates, format options, or quality defaults; this is a significant gap because the schema alone is insufficient.

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 states a clear action ('Capture') and resource ('screenshot'), so the tool's primary purpose is evident. However, it offers no differentiation from sibling tools such as vnc_ocr_region or vnc_find_image, which also involve image capture or analysis.

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?

There is no guidance on when to use this tool versus alternatives. No mention of scenarios, exclusions, or references to sibling tools; the description simply states the action without context.

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