Playwright MCP

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

Annotations provide readOnlyHint=false, openWorldHint=true, and destructiveHint=true. The description adds context about the multi-action nature (list, create, close, select) and implies destructive behavior for 'close' action. However, it doesn't elaborate on rate limits, authentication needs, or specific destructive consequences beyond what annotations already indicate.

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 (one sentence) and front-loaded with all key information. Every word earns its place by listing the four possible actions. No redundant or verbose language is present.

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 with different behaviors), rich annotations, and 100% schema coverage, the description is minimally adequate. However, it lacks output information (no output schema provided) and doesn't explain result formats or error conditions. For a multi-action tool with destructive operations, more context would be helpful.

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 documentation. The description adds no additional parameter semantics beyond what's in the schema. It mentions the actions but doesn't explain parameter usage, constraints, or interactions beyond the schema's enum and description. Baseline 3 is appropriate given complete schema coverage.

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). It distinguishes from siblings by focusing on tab management rather than navigation, interaction, or monitoring. However, it doesn't explicitly differentiate from all siblings (e.g., browser_close could be ambiguous).

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. It doesn't mention when to use browser_tabs versus browser_close for closing tabs, or when to use browser_navigate versus creating a new tab. No context about prerequisites, sequencing, or exclusions is provided.

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