file_tools is a Fetch Hive system MCP tool that is added to every agent automatically. It cannot be disabled or removed. Fetch Hive attaches the provider-facing file tools to a run only when the turn has document attachments, history file context, or asks to generate or export a file.
Uploaded CSV, XLSX, PDF, DOCX, text, and Markdown attachments are exposed to the agent as an <available_files> manifest. The agent should call read_file before relying on document contents. read_file can only access URLs that were supplied as structured attachments in the current request or conversation history.
Public API callers can pass attachments as HTTPS URL strings or as objects with
file_url, file_name, and file_type. URL strings are enough for most
calls; Fetch Hive infers metadata from the URL when it can, and extensionless
upload URLs are still allow-listed for read_file.
When the current turn asks to generate or export a file, agents can call write_file to create PDF, DOCX, or XLSX files. For PDF and DOCX files, markdown content is recommended and preserves common document structure such as headings, paragraphs, lists, emphasis, code blocks, blockquotes, horizontal rules, and simple tables. Generated files are uploaded through Rails, stored as account assets, and returned as public asset URLs. File tool calls are recorded in traces and completions as read_file and write_file sources.
