pick_element

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

With no annotations, the description carries full burden. It discloses the interactive nature (hover highlight, waiting for click), return data, and environment requirement. It does not mention potential side effects, but the tool appears non-destructive. Slightly lacking in not stating that no changes are made to the page.

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 sentences: first explains the tool's core functionality, second gives usage guidance. No wasted words, information is front-loaded.

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 and no output schema, the description covers what it does, when to use, prerequisites, and return value. Nothing essential is missing.

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 description does not add significant value beyond the schema's description of timeoutSeconds, which is already well-documented. Schema coverage is 100%, so baseline 3 is appropriate.

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 explicitly states it turns on a DevTools-style hover highlight, waits for user click, and returns the clicked element's uid and ancestor chain. This clearly differentiates from sibling tools like find_elements or annotated_screenshot which are automated.

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?

It explicitly says to use when the user says 'I'll show you' or when find_elements/annotated_screenshot fail, and notes the requirement for a visible browser window. This provides clear context for when to use vs alternatives.

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