browser_screenshot

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

Annotations indicate readOnlyHint=true, which is consistent. The description adds behavioral context: captures a PNG, can target full page or element, and is used for diagnosis. No contradictions.

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?

Two paragraphs, four sentences total. First sentence is a clear purpose statement. Every sentence adds value without repetition or fluff.

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?

For a simple screenshot tool with one parameter and no output schema, the description adequately covers purpose, usage, parameter semantics, and behavioral traits. No missing critical information.

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 covers the selector parameter with description (CSS selector, default empty = full page). Description adds meaning by explaining how to isolate a component and giving examples (header, nav, modal). Since schema coverage is 100%, baseline is 3, but description elevates it.

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 it takes a PNG screenshot for visual/layout/CSS diagnosis, with a specific verb and resource. It distinguishes from other browser tools by mentioning screenshot functionality, which is unique among siblings.

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 explains when to use (full page for layout diagnosis or specific element via CSS selector) and provides concrete examples like misaligned elements, invisible text, broken layouts. It does not explicitly mention when not to use, but the guidance is clear.

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