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. While it mentions the tool can 'log calls, modify arguments, or change return values,' it fails to describe critical behaviors: whether hooking persists across sessions, potential performance impacts, error handling, or security implications. For a powerful hooking tool with zero annotation coverage, 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 front-loads the core action ('Hook a specific function') and lists key capabilities without unnecessary elaboration. Every word earns its place, making it easy to parse quickly while conveying essential information.

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 a function-hooking tool with no annotations and no output schema, the description is incomplete. It lacks information on return values, error conditions, side effects (e.g., whether hooks affect system stability), and dependencies like requiring a valid session_id. For a tool with five parameters and significant behavioral implications, this leaves too many unknowns for reliable agent use.

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 80%, with clear descriptions for most parameters (e.g., 'Module name (or null for main executable)'). The description adds minimal value beyond the schema by implying that 'on_enter' and 'on_leave' parameters are for JavaScript code to run at function entry/exit, but this is already suggested by the schema. Since the schema does most of the work, the baseline score of 3 is appropriate.

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 ('hook', 'log', 'modify', 'change') and identifies the resource ('a specific function'). It distinguishes itself from siblings like frida_trace or frida_intercept_method by specifying the capability to modify arguments and return values, not just tracing. However, it doesn't explicitly differentiate from frida_java_hook_method or frida_objc_hook_method, which are similar but language-specific.

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 prerequisites like needing an active Frida session, nor does it compare with siblings such as frida_trace (for tracing only) or frida_java_hook_method (for Java-specific hooking). Without this context, an agent might misuse it in inappropriate scenarios.

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