browser_evaluate

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

No annotations are provided, so the description must carry the burden. It states that the tool evaluates JavaScript and returns a result but does not disclose important behavioral details like whether it waits for promises, error handling, or requirement for page interactivity.

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 concise at about 5 lines, with clear sections for Args and Returns. It is front-loaded with the main purpose and is efficiently structured, though minor improvements could be made.

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 has 3 parameters and an output schema, the description explains parameter usage but lacks behavioral transparency and edge case handling. The output schema covers return values, so the description is mostly complete but not fully.

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?

With 0% schema description coverage, the description adds significant meaning by specifying the function format, distinguishing between element (human-readable) and ref (exact reference). It clarifies usage beyond the raw schema but could be more detailed about function scope and return types.

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 'Evaluate JavaScript expression on page or element,' providing a specific verb and resource. It distinguishes itself from sibling tools like browser_click or browser_snapshot, which perform different actions.

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 explains the format of the function and the optional use of element and ref, providing some usage context. However, it lacks explicit guidance on when to choose this tool over alternatives (e.g., for dynamic evaluation vs static snapshot) and does not state when not to use it.

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