Browser 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 states what the tool does but lacks critical details: it doesn't mention whether this executes in a specific page context, what permissions or prerequisites are needed, if there are security implications, rate limits, or what happens on errors. For a tool that executes arbitrary code, this is a significant gap in transparency.

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 a single, efficient sentence that directly states the tool's purpose. The parenthetical reference to 'browser_docs' adds context without clutter. However, it could be more front-loaded by explicitly mentioning key constraints or use cases upfront.

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 executing JavaScript in a browser (with potential side effects, security risks, and context dependencies), the description is incomplete. With no annotations, no output schema, and minimal behavioral details, it fails to provide sufficient context for safe and effective use. The reference to 'browser_docs' hints at more information but doesn't compensate for the gaps in the description itself.

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?

The input schema has 100% description coverage, with the 'code' parameter clearly documented as 'JavaScript code to execute'. The description adds no additional parameter semantics beyond what the schema provides, so it meets the baseline of 3 for adequate but not enhanced parameter understanding.

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 action ('Execute JavaScript') and context ('in the browser context'), providing a specific verb+resource combination. However, it doesn't differentiate from sibling tools like browser_console_get or browser_get_dom that might also involve JavaScript execution or browser interaction, making it less than fully distinctive.

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 implies usage for executing JavaScript in a browser, but provides no explicit guidance on when to use this tool versus alternatives like browser_console_get for console output or browser_get_dom for DOM manipulation. The reference to 'browser_docs' suggests additional context might be available, but this isn't elaborated in the description itself.

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