Playwright Browserbase MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively explains that actions should be atomic and specific, warns against multi-step actions, and advises using 'observe' when unsure. However, it lacks details on error handling, timeouts, or what happens if the element is not found, which are important for a web automation tool.

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 front-loaded with the core purpose, followed by specific examples and avoidance guidelines. It is appropriately sized with two sentences, but the second sentence is lengthy and could be split for better readability without losing clarity.

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 complexity of web automation and no annotations or output schema, the description does well by covering purpose, usage, and behavioral traits. However, it could improve by mentioning potential side effects (e.g., page navigation after a click) or response format, though the lack of output schema makes this less critical.

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 schema already documents both parameters thoroughly. The description does not add significant meaning beyond the schema, as it repeats the same examples and guidelines for the 'action' parameter. Baseline 3 is appropriate when the schema does the heavy lifting.

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 tool 'performs an action on a web page element' with specific examples like 'Click the sign in button' or 'Type 'hello' into the search input'. It distinguishes from siblings by focusing on atomic actions versus navigation (browserbase_stagehand_navigate) or observation (browserbase_stagehand_observe).

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 explicit guidance on when to use this tool ('Act actions should be as atomic and specific as possible') and when not to use it ('AVOID actions that are more than one step'). It also references the sibling tool 'observe' with 'If unsure, use observe before using act,' offering clear alternatives.

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