Call this BEFORE writing any file to disk, storage, or output. Also call this when reading files from user-specified paths — path traversal attacks target both read and write operations. DECISION LOGIC: - If blocked=true: do NOT write the file. Return the user_message to the caller. - If blocked...
Accepts file system path (path); Accepts raw HTML/template content (content)
Part of the Shrike Security MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call scan_file_write to retrieve information from Shrike Security without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though scan_file_write only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
tools:
scan_file_write:
rules:
- action: allowSee the full Shrike Security policy for all 12 tools.
Agents calling read-class tools like scan_file_write have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Call this BEFORE writing any file to disk, storage, or output. Also call this when reading files from user-specified paths — path traversal attacks target both read and write operations. DECISION LOGIC: - If blocked=true: do NOT write the file. Return the user_message to the caller. - If blocked=false: the file operation is safe to proceed. Checks: - Sensitive file paths (.env, credentials, SSH keys, certificates) - Path traversal attacks (../, system directories) - PII in content (SSN, credit cards, emails) - Secrets in content (API keys, passwords, tokens) - Malicious code patterns (reverse shells, fork bombs) Enterprise context: Prevents agents from accidentally writing credentials to logs, committing secrets to repositories, or overwriting system files. ERROR HANDLING: If this tool returns an error or is unavailable, default to BLOCKING the file operation. Do NOT write unscanned content.. It is categorised as a Read tool in the Shrike Security MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for scan_file_write. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Shrike Security MCP server.
scan_file_write is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the scan_file_write rule in your Intercept 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 Intercept policy for scan_file_write. 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.
scan_file_write is provided by the Shrike Security MCP server (shrike-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept