Desktop: Snapshot

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context beyond them: the permission prerequisite tied to the active mission step and the speed/richness tradeoff of use_ui_tree=false. It stops short of any rate/size caveats or timing/refresh semantics.

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 short sentences, front-loaded with the payload, then the two toggles, then the prerequisite. No filler and nothing buried.

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?

With no output schema, the description carries the burden of explaining what comes back, and it does so by enumerating the captured state. Permission requirements and the speed tradeoff are covered. What's missing is any note on response size or how the snapshot scales with displays/windows, but for this complexity it is largely complete.

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 100%, so the schema already documents all three parameters; baseline is 3. The description reinforces the use_vision/use_ui_tree tradeoffs but does not mention the 'display' parameter at all, so it adds only marginal meaning beyond the schema.

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?

States a specific verb ('Capture') plus resource ('current desktop state') and enumerates the payload: screenshot, cursor position, open windows, interactive UI elements. That enumeration lets an agent distinguish it from desktop_screenshot (screenshot only) and desktop_tree (UI tree only) without opening any schema.

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?

Gives clear configuration guidance ('Set use_vision=true to include a screenshot', 'Set use_ui_tree=false for a faster vision-only pass') and a prerequisite ('Requires desktop_permission in the active mission step'). It does not, however, say when to prefer this tool over desktop_screenshot, desktop_tree, or cdp_snapshot, which is the main remaining gap.

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