browser_screenshot

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

No annotations are provided, so the description must fully disclose behavior. It states the output format (PNG) and the three modes, but fails to mention what is returned (e.g., base64 string, file path) or other important behaviors like overwriting behavior. This is insufficient for an unannotated tool.

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?

Extremely concise: two sentences front-loaded with the core purpose. Every word adds value, and the structure is clear (default behavior then options).

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 tool, the description covers the main functionality (viewport, full page, element). However, it omits the return value format, which is critical since there is no output schema. Given the lack of annotations and output schema, the description is somewhat incomplete.

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%, so the description must compensate. It adds meaning for 'full_page' (captures entire scrollable page) and 'ref' (captures single element), but does not explain 'session_id'. This is a partial compensation, slightly below the baseline of 4 for 0% coverage.

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?

Clearly states it takes a PNG screenshot and describes three capture modes (viewport, full page, single element). However, it does not differentiate from sibling tools like browser_snapshot which may also capture screenshots, potentially confusing the agent.

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 when to use each mode (e.g., full_page=True for scrolling pages) but provides no explicit guidance on when to use this tool versus alternatives, nor when not to use it. Siblings such as browser_snapshot are not mentioned.

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