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frida_trace_method

Destructive

Registers bounded call tracing for a class method, optionally capturing scalar arguments, return addresses, and in-context stacks to inspect iOS runtime behavior.

Instructions

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "device_id": "<device_id>",
      "session_id": "<session_id>",
      "class_name": "<class_name>",
      "selector": "<selector>"
    },
    "name": "frida_trace_method"
  }
}

Input Schema

Name	Required	Description	Default
`selector`	Yes
`backtrace`	No
`device_id`	Yes
`class_name`	Yes
`max_events`	No
`session_id`	Yes
`class_method`	No
`capture_return`	No
`capture_arguments`	No

Output Schema

Name	Required	Description	Default
`ok`	Yes
`data`	No
`error`	No
`elapsed_ms`	Yes
`request_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 23, 2026

TDQS

C2.9/5.0

Behavior3/5

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known. The description adds that tracing is bounded and capture is optional, but it omits operational details such as hook installation side effects, required cleanup via frida_unhook, or performance impact.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no filler. It is appropriately concise, though somewhat terse given the tool's nine parameters and destructive behavior.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a destructive tracing tool with nine parameters and no schema descriptions, the definition omits prerequisites, workflow context, and parameter meanings. The presence of an output schema reduces the need to explain return values, but the overall context is still inadequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate but only loosely maps to capture_arguments, capture_return, and backtrace. It leaves required identifiers (device_id, session_id, class_name, selector) and settings like max_events and class_method unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Register') and resource ('call tracing'), making the core operation identifiable. However, it does not explicitly say it hooks a class method/selector, nor does it distinguish itself from siblings like frida_get_events or frida_unhook.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus alternatives, no mention of prerequisites such as an existing session or device, and no indication of how it relates to frida_get_events or frida_unhook.

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