Code 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 the tool executes JavaScript with Node.js but fails to mention critical traits like security implications (e.g., sandboxing, permissions), performance aspects (e.g., timeouts, resource limits), or output handling (e.g., console logs, errors). This leaves significant gaps for an agent to understand the tool's behavior.

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 with zero waste, front-loading the core functionality. It is appropriately sized for the tool's purpose, making it easy to parse without unnecessary elaboration.

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 arbitrary JavaScript code, no annotations, and no output schema, the description is insufficient. It lacks details on safety, error handling, return values, or dependencies, making it incomplete for an agent to use the tool effectively in context with sibling tools.

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 clear parameter definitions (code, script_path, args). The description adds no additional meaning beyond the schema, such as explaining parameter interactions (e.g., using code vs. script_path) or constraints. Baseline 3 is appropriate as the schema adequately documents parameters.

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') and resource ('JavaScript code or script with Node.js'), providing a specific verb+resource combination. However, it doesn't distinguish this tool from sibling tools like 'run_python' or 'run_command' that also execute code, missing explicit differentiation.

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 is provided on when to use this tool versus alternatives such as 'run_python' for Python code or 'run_command' for shell commands. The description lacks context about appropriate use cases or exclusions, offering no usage instructions.

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