ui_screenshot

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the safety profile is covered externally. The description adds that output is a PNG inside the workspace, but it does not disclose overwrite behavior, file-write side effects, or session/auth requirements.

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 with no filler, but it is too terse for a destructive file-writing tool. The brevity reflects under-specification rather than optimal sizing.

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 and no parameter descriptions in the schema, the description should compensate by explaining sessionId, path, and file-write behavior. It leaves the required session parameter, optional path default, and overwrite risk unaddressed.

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 names sessionId or path. 'Active target' loosely hints at the session and 'inside the workspace' loosely hints at path, but the required session identifier and default output path remain unexplained.

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 artifact: capture the active target to a PNG inside the workspace. It is clear what the tool produces, but it does not distinguish this from sibling tools like ui_snapshot or clarify exactly what 'active target' means.

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 instead of ui_snapshot, ui_action, or other UI tools. It also omits prerequisites, such as needing an active session before calling it.

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