Edits the specified file with the given modifications. This tool marks files that need to be edited with the specified changes. Args: file_path: The absolute path to the file to modify. old_string: The exact literal text to replace. Must uniquely identify the single instance to change. Should inc...
AI agents use edit to create or update resources in Claude Context — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Claude Context environment.
This tool creates or modifies files reversibly within a codebase. While modifications to source code are reversible (via version control), the tool enables an AI agent to alter application logic, introduce vulnerabilities, or inject malicious code into any file in the repository.
From the tool's definition Tool description explicitly states it 'Edits the specified file with the given modifications' and 'marks files that need to be edited with the specified changes.' Parameters include file_path and old_string/new_string for replacement operations.
Documented attack patterns abuse exactly the kind of access edit gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Context, and nothing reaches the server without passing your rules. This is the rule we recommend for edit:
{
"version": "1",
"default": "deny",
"tools": {
"edit": {
"limits": [
{
"counter": "edit_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}edit 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.
Free to start. No card required.
Edits the specified file with the given modifications. This tool marks files that need to be edited with the specified changes. Args: file_path: The absolute path to the file to modify. old_string: The exact literal text to replace. Must uniquely identify the single instance to change. Should include at least 3 lines of context before and after the target text, matching whitespace and indentation precisely. If old_string is empty, the tool attempts to create a new file at file_path with new_string as content. new_string: The exact literal text to replace old_string with. Returns: A string indicating the file has been successfully modified. It is categorised as a Write tool in the Claude Context MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Claude Context MCP server in PolicyLayer and add a rule for edit: 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 Claude Context. Nothing to install.
edit is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the edit 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.
Set action: deny in the PolicyLayer policy for edit. 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.
edit is provided by the Claude Context MCP server (zilliztech/claude-context). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Claude Context tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
7 Claude Context tools catalogued and risk-classified — across an index of 42,500+ MCP servers.