browser_screenshot

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

No annotations are provided, so the description carries the full burden. It only states the scope (page or iframe) and does not disclose the output format, whether it captures the full page or viewport, or any side effects. This is insufficient for a tool with no annotation support.

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 concise sentence that is front-loaded with the verb and resource. It contains no fluff or unnecessary details, making it appropriately sized for a simple tool.

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 the low complexity (1 optional param, no output schema, no annotations), the description covers the core action but lacks crucial context about the return value (e.g., image path vs base64) and any behavioral constraints. It is minimally viable but not fully 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?

The schema describes frameSelector as an optional iframe selector, matching the description's mention of 'specific iframe'. Since schema coverage is 100%, the baseline is 3; the description adds no extra semantics 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?

The description clearly states the tool takes a screenshot of the page or a specific iframe, using the specific verb 'take' and identifying the resource. This distinguishes it from siblings like browser_snapshot (DOM snapshot) and browser_frame_bbox (bounding box).

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 implies usage by stating what it does (screenshot) but does not explicitly guide when to use it over alternatives like browser_snapshot. No exclusions or contextual triggers are provided, so it remains at the 'implied usage' level.

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