change_signature

Change a function/method signature (add/remove/rename/reorder parameters) and update all call sites. Dry-run by default (safe preview). Modifies source files. Use plan_refactoring with type=

SERVERTrace SOURCEnikolai-vysotskyi/trace-mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/nikolai-vysotskyi-trace-mcp/change-signature.md

WHAT IT DOES

What change_signature does on Trace

AI agents use change_signature to create or update resources in Trace, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Trace environment.

RISK

Why change_signature is rated Medium

This tool modifies source files by changing function/method signatures and updating all call sites across the codebase. While it has a dry-run default making it reversible in principle, the actual execution modifies potentially many source files simultaneously. This is a Write operation (reversible modification) rather than Destructive since changes can be undone via version control.

From the tool's definition Change a function/method signature (add/remove/rename/reorder parameters) and update all call sites. Dry-run by default (safe preview). Modifies source files.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs change_signature safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Trace, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For change_signature, this is the rule to start with:

change_signature Rate-limited

change_signature stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "change_signature": {
      "limits": [
        {
          "counter": "change_signature_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Trace, apply this rule, and every change_signature call is checked against it from then on.

FAQ

Questions about change_signature

What does the change_signature tool do? +

Change a function/method signature (add/remove/rename/reorder parameters) and update all call sites. Dry-run by default (safe preview). Modifies source files. Use plan_refactoring with type=. It is categorised as a Write tool in the Trace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on change_signature? +

Register the Trace MCP server in PolicyLayer and add a rule for change_signature: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Trace. Nothing to install.

What risk level is change_signature? +

change_signature is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit change_signature? +

Yes. Add a rate_limit block to the change_signature rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block change_signature completely? +

Set action: deny in the PolicyLayer policy for change_signature. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides change_signature? +

change_signature is provided by the Trace MCP server (nikolai-vysotskyi/trace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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