take_snapshot

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

Beyond the readOnlyHint annotation, the description discloses important behavioral details: UIDs remain valid until element removal or navigation, output is capped at maxLines, selector scoping is available, and saveTo dumps the full tree. This provides a meaningful behavioral contract without contradicting the annotation.

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?

Two compact sentences, front-loaded with the core action, and every clause carries unique information. There is no filler or repetition of schema content beyond what is useful for orientation.

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 no output schema and 8 optional parameters, the description covers purpose, UID semantics, output-limiting behavior, scoping, and full-tree handling. It could be slightly more explicit about the exact return shape (e.g., whether output is a text tree containing UIDs), but the core contract is sufficiently clear.

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 already documents all 8 parameters with detailed descriptions. The tool description adds extra value by connecting maxLines default, selector scoping, and saveTo as a way to get the full tree, which helps the agent choose between inline and file output.

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?

Description uses a specific verb ('Capture') with a clear resource ('DOM snapshot') and defines the key outcome ('stable UIDs'). This distinguishes it from visual captures like screenshot_page and UID-using sibling actions like click_by_uid or fill_by_uid.

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 clearly implies this tool produces UIDs used by sibling UID-based tools and explains UID stability across snapshots. It does not, however, explicitly state when to prefer this over alternatives like screenshot_page or resolve_uid_to_selector, nor does it mention exclusions.

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