desktop_observe

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

The readOnlyHint annotation already establishes safety, and the description adds meaningful behavioral detail: coordinate systems differ between image pixels and native X11 root pixels, image_bounds can be null, snapshot IDs expire after 15 seconds, and integer image points should be used. This goes beyond what the annotation provides.

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 tight and information-dense, with the main return value front-loaded. Each sentence adds distinct technical detail, though the coordinate-system explanations are packed into a single sentence and may be hard to parse. Still, there is no wasted text.

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 there is no output schema, the description carries the burden of explaining return-ish behavior and does cover screenshot, window layout, snapshot ID, coordinate systems, and null bounds. However, it omits the effect of max_width and does not describe the structure or shape of the returned window layout or snapshot ID, leaving gaps for an agent invoking this tool.

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 0%, and the description never mentions max_width, which is the only parameter. Although the parameter name and default are somewhat self-explanatory, the description does not compensate for the schema gap by explaining how max_width affects the returned screenshot or when an agent should override the default.

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 specific verb and resource: it returns a screenshot, window layout, and a 15-second snapshot ID. This clearly identifies the tool as an observation/capture function and is distinct enough from siblings like desktop_status or desktop_ocr, though it does not explicitly name alternatives.

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 no guidance on when to use this tool versus the many sibling tools. It explains coordinate conventions and pixel mapping, which is useful after the tool is selected, but it does not help an agent decide between desktop_observe, desktop_status, desktop_report, or desktop_inspect.

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