Frida MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool evaluates JavaScript in a Frida runtime, implying it's a read/write operation that could affect the process, but doesn't disclose critical traits like potential side effects (e.g., memory modification, crashes), authentication needs, rate limits, or error handling. The description is minimal and lacks behavioral context beyond the basic action.

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 function without unnecessary words. It's appropriately sized and front-loaded, making it easy to understand at a glance. Every part of the sentence contributes to clarifying the purpose, earning its place.

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 evaluating arbitrary JavaScript in a runtime (a potentially powerful and risky operation), the description is incomplete. No annotations are provided to cover safety or behavioral traits, and there's no output schema to explain return values. The description lacks details on prerequisites (e.g., how to attach a process), error cases, or example usage, making it inadequate for safe and effective tool invocation.

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 50% (only the 'code' parameter has a description). The description adds no additional parameter semantics beyond what's in the schema—it doesn't explain what 'session_id' means or provide context for the JavaScript code. With partial schema coverage, the description doesn't compensate for the undocumented 'session_id' parameter, resulting in a baseline score of 3 due to the schema handling some documentation.

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: 'Evaluate arbitrary JavaScript in the Frida runtime of an attached process.' It specifies the verb ('evaluate') and resource ('JavaScript'), and distinguishes it from siblings by focusing on runtime evaluation rather than attachment, inspection, or other operations. However, it doesn't explicitly differentiate from similar tools like frida_inject_script or frida_rpc_call, which might also involve code execution.

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 mentions 'attached process,' implying a prerequisite, but doesn't specify when to choose this over other code-execution tools like frida_inject_script or frida_rpc_call. There are no explicit when/when-not instructions or named alternatives, leaving usage context unclear.

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