Playwright MCP

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

Annotations provide readOnlyHint=false, destructiveHint=true, and openWorldHint=true, indicating mutable and potentially destructive operations. The description adds value by specifying actions (list, create, close, select), which clarifies behavioral scope beyond annotations, though it doesn't detail side effects like what happens on close or creation defaults.

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 extremely concise and front-loaded, listing all key actions in a single, efficient sentence with zero wasted words. It directly communicates the tool's capabilities without redundancy or fluff.

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 moderate complexity (multiple actions, destructive potential) and lack of output schema, the description is minimally adequate. It covers what the tool does but lacks details on return values, error conditions, or interaction with browser state, leaving gaps for an AI agent to infer behavior.

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%, with clear parameter descriptions (e.g., 'Operation to perform' for action, details on index usage). The description adds no additional parameter semantics beyond the schema, but the schema is comprehensive, so a baseline score of 3 is appropriate as it doesn't compensate unnecessarily.

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's purpose with specific verbs (list, create, close, select) and resource (browser tab), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like browser_close or browser_navigate, which could handle similar operations.

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 no guidance on when to use this tool versus alternatives. With siblings like browser_close (for closing) and browser_navigate (for creating/selecting via navigation), there's no indication of context, prerequisites, or trade-offs for choosing this multi-action tool over specialized ones.

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