Playwright MCP

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

Annotations provide readOnlyHint=true, destructiveHint=false, and openWorldHint=true, indicating a safe read operation with potentially unbounded results. The description adds value by specifying 'all console messages' (implying comprehensive retrieval), which complements the openWorldHint about unbounded data. No contradiction with annotations, and it provides useful context about scope.

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?

Extremely concise with a single sentence that directly states the tool's function. No unnecessary words or structural fluff. Every word earns its place by conveying essential information efficiently.

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 simplicity (0 parameters, read-only operation with annotations), the description is minimally adequate. However, it lacks details about what 'console messages' includes (e.g., logs, errors, warnings), whether it's real-time or historical, and there's no output schema to clarify return values. For a tool that retrieves data, more context about the data format 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?

There are 0 parameters, and schema description coverage is 100%. The description doesn't need to explain parameters, and it appropriately doesn't mention any. A baseline of 4 is appropriate for a zero-parameter tool where the schema fully covers the input structure.

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 'Returns all console messages' clearly states the action (returns) and resource (console messages). It distinguishes from most siblings that perform browser interactions (click, navigate, type) but doesn't explicitly differentiate from browser_network_requests which also returns data. The purpose is specific but could be more precise about what 'console messages' refers to.

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?

No guidance on when to use this tool versus alternatives. The description doesn't mention prerequisites (e.g., needing an active browser session), appropriate contexts, or when other tools might be more suitable. It's a standalone statement with no usage context.

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