screenshot

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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context by mentioning the underlying CDP mechanism and the 'orient yourself' purpose, but it does not describe the return format (e.g., base64, file path), pagination, or any side effects. For a screenshot tool, the core behavior is implied, but the lack of output details is a moderate gap.

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 exceptionally concise: two sentences with no wasted words. The action is front-loaded, and the usage tip ('Call this first') is a valuable addition. 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 simple tool with one optional parameter, the description covers the main purpose, the parameter's role, and a practical usage suggestion. The lack of return format is a minor omission, but given the simplicity and the absence of an output schema, the description provides sufficient context for an agent to use the tool.

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 has zero description coverage for the element_id parameter, but the description explicitly explains its purpose: capturing a specific element by ID when provided, and the full page when omitted. This compensates well for the schema's lack of detail.

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 action ('Capture a screenshot') and the scope ('of the webview page (or a specific element by ID)'). It distinguishes the tool from siblings like get_dom_tree or get_element_info by focusing on visual capture. The verb-object pair is specific and unambiguous.

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 phrase 'Call this first to orient yourself' provides explicit guidance on when to use the tool, suggesting it is the initial step in a visual workflow. However, it does not mention alternatives or exclusions, such as using get_dom_tree for structural navigation, so it lacks full differentiation.

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