screenshot

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

With no annotations, the description carries the full burden. It discloses a key behavioral trait: capturing a specific tab via CDP does not switch focus. It also distinguishes the default IPC path. However, it does not mention potential side effects like file creation/overwriting or whether the capture is full-page or viewport-only, which would be additional useful context.

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 two sentences, front-loaded with the main action, and zero wasted words. The conditional logic is conveyed efficiently without redundancy.

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 tool's simplicity, the description plus well-covered schema parameters are sufficient for an agent to invoke the tool. It lacks an explicit note about the output file behavior (e.g., overwriting, return value) and full-page vs viewport capture, but these are not critical gaps. Overall, it is complete enough for typical usage.

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 100%, so the baseline is 3. The description adds some conditional logic for the 'tab' parameter ('if specified') and the default behavior, but this largely mirrors the schema descriptions. It does not introduce significant new parameter semantics beyond what the schema already provides.

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 'Take a screenshot of a page' with a specific verb and resource, and immediately distinguishes the two capture modes (specific tab via CDP vs currently focused tab via IPC). This uniquely identifies the tool among siblings like list_tabs and navigate, which have different purposes.

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 provides clear context for when to use each mode: 'If tab is specified' versus 'Otherwise captures the currently focused tab.' While it doesn't explicitly mention alternatives among sibling tools, there is no other screenshot tool, so usage guidance is effectively inherent. It lacks an explicit when-not-to-use statement but is otherwise informative.

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