screenshot

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states the output format (PNG) and target (page or element) but omits details like whether it waits for page load, captures viewport vs full page by default, or interacts with scrolling. No mention of permissions or side effects.

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?

Single sentence of 8 words, no redundancy or filler. The most essential information (action, format, target) is front-loaded. Every word earns its place.

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 tool with 4 parameters, no output schema, and no annotations, the description is insufficient. It does not explain what is returned (presumably image data), how fullPage differs from viewport, or how ref/selector affect behavior. Compared to sibling tools like 'navigate' or 'click', this description lacks depth needed for correct invocation.

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 75% (3 of 4 params documented). The description adds 'PNG' format and 'element' scope, which are not in schema. However, it does not explain the mutual exclusivity of ref and selector (already in schema) or the effect of fullPage. Baseline 3 is appropriate since schema already covers most parameter semantics.

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 'Capture a PNG screenshot (page or element)' – a specific verb and resource with format and scope. However, it does not differentiate from sibling 'snapshot' tool which may have overlapping functionality.

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?

No guidance on when to use this tool versus alternatives like 'get_html', 'get_text', or 'snapshot'. The description implies capturing a screenshot but offers no context for choosing between page vs element or when to use ref vs selector.

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