// MCP TOOL REFERENCE

register_tools

ServerIntervals Icu MCP Server
CategoryExecute

WHAT IT DOES

What register_tools does on Intervals Icu MCP Server

AI agents invoke register_tools to trigger actions in Intervals Icu MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

THE RISK

High Risk

Why register_tools needs a policy

This tool dynamically imports modules and registers tools with a server instance, which is an execution/configuration operation that modifies the running server's capabilities. It doesn't simply read data, but actively triggers code execution (imports and decorator registration). Misuse could expose unintended tools or alter the server's attack surface.

From the tool's definition 'Register all MCP tools with the FastMCP server instance' and 'causes their @mcp.tool() decorators to register the tools'

Documented attack patterns abuse exactly the kind of access register_tools gives an agent:

POLICY

How to control register_tools

PolicyLayer is an MCP gateway — it sits between your AI agents and Intervals Icu MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for register_tools:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "register_tools": {
      "limits": [
        {
          "counter": "register_tools_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

register_tools stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register Intervals Icu MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Intervals Icu MCP Server tools

Destructive delete_custom_item Delete a custom item for an athlete from Intervals.icu Args: item_id: The cus Destructive delete_event Delete event for an athlete from Intervals.icu Args: athlete_id: The Intervals Destructive delete_events_by_date_range Delete events for an athlete from Intervals.icu in the specified date range. Args: Write add_activity_message Add a message (note/comment) to an activity on Intervals.icu Args: activity_i Write add_or_update_event add_or_update_event Write add_or_update_note Add or update a plain text note (category NOTE) on the Intervals.icu calendar. Args: Write create_custom_item create_custom_item Write update_custom_item update_custom_item

All 21 Intervals Icu MCP Server tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Intervals Icu MCP Server → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about register_tools

What does the register_tools tool do? +

Register all MCP tools with the FastMCP server instance. This function imports all tool modules, which causes their @mcp.tool() decorators to register the tools. The tools need access to the mcp instance, so they will be imported after the mcp instance is created. Args: mcp_instance (FastMCP): The FastMCP server instance to register tools with. It is categorised as a Execute tool in the Intervals Icu MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on register_tools? +

Register the Intervals Icu MCP Server MCP server in PolicyLayer and add a rule for register_tools: 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 Intervals Icu MCP Server. Nothing to install.

What risk level is register_tools? +

register_tools is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit register_tools? +

Yes. Add a rate_limit block to the register_tools 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 register_tools completely? +

Set action: deny in the PolicyLayer policy for register_tools. 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 register_tools? +

register_tools is provided by the Intervals Icu MCP Server MCP server (mvilanova/intervals-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Intervals Icu MCP Server tool call.

Start from Intervals Icu MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →

Free to start. No card required.

21 Intervals Icu MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.