compact_context · Pathfinder MCP Server MCP: Risk & Policy

WHAT IT DOES

What compact_context does on Pathfinder MCP Server

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

WHY IT NEEDS A POLICY

Why compact_context needs a policy

The tool writes/creates summary artifacts by compressing existing context. It modifies the session state by replacing or supplementing detailed context with compressed summaries. This is reversible in the sense that original data may still exist, making it a Write operation rather than Destructive. Blast radius is low since it only affects in-session context management, not external systems or persistent data stores.

From the tool's definition 'Compress session context into summary artifacts' — creates new summary artifacts from existing session data

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

compact_context Rate-limited

compact_context 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": {
    "compact_context": {
      "limits": [
        {
          "counter": "compact_context_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Pathfinder MCP Server, so you can run agents against it safely.

FAQ

Questions about compact_context

What does the compact_context tool do? +

Compress session context into summary artifacts. It is categorised as a Write tool in the Pathfinder MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on compact_context? +

Register the Pathfinder MCP Server MCP server in PolicyLayer and add a rule for compact_context: 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 Pathfinder MCP Server. Nothing to install.

What risk level is compact_context? +

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

Can I rate-limit compact_context? +

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

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

compact_context is provided by the Pathfinder MCP Server MCP server (jamesctucker/pathfinder-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.