ui_take_screenshot

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

Annotations already declare readOnlyHint and idempotentHint, so the description adds value by describing return format (inline ImageContent + TextContent) and the need to resume execution. However, it doesn't detail potential side effects or authorization needs beyond what annotations imply.

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 well-organized with a clear lead sentence, return info, bulleted use cases, and a practical note. Each part earns its place; no redundancy. Could be slightly more concise, but effective.

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?

Despite lacking an output schema, the description thoroughly explains return types and metadata. It covers parameter details and common pitfalls (stopped app). For a simple screenshot tool, this is adequately 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 coverage is 0%, but the description provides meaningful defaults ('Default 1280; max useful is 1568') and format options ('webp (smallest), jpeg, png'). This adds significant value beyond the schema's bare parameter names.

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 clearly states 'take a screenshot of the debugged application's window' with specific verb and resource. It distinguishes itself from the sibling 'ui_take_annotated_screenshot' by emphasizing raw visual state and mentioning inline ImageContent vs. annotations.

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 lists specific use cases (verifying UI, finding missing elements, layout, rendering issues) and a prerequisite (resume if at breakpoint). While it doesn't explicitly contrast with all alternatives, the use cases are clear and actionable.

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