Tools

Tool (pycodeloop.abc.tool.Tool) is the interface for any action the agent can take:

class Tool(ABC):
    name: str
    description: str
    parameters: dict            # JSON schema
    dangerous: bool = False

    def schema(self) -> dict: ...
    def preview(self, **kwargs) -> str: ...
    def run(self, **kwargs) -> ToolResult: ...

Built-in tools

Tool	Purpose	dangerous
read_file	Read a file, optionally a line range	No
write_file	Create or overwrite a file	Yes
edit_file	Replace an exact substring in a file	Yes
delete_file	Delete a file	Yes
list_dir	List a directory	No
glob	Find files matching a glob pattern	No
grep	Regex search across files	No
bash	Run a shell command with a timeout	Yes
web_fetch	Fetch a URL and extract its text	No
http_request	Call a JSON HTTP API — any method, headers, body	Yes
git_status	git status --porcelain=v1 --branch	No
git_diff	Unstaged (or staged) changes as a unified diff	No
git_log	Recent commit history, one line per commit	No
git_commit	Stage files and create a commit	Yes
env	Read environment variables (sensitive values masked)	No
todo	Scratchpad checklist for multi-step tasks	No

DEFAULT_TOOLS (pycodeloop.core.tools.DEFAULT_TOOLS) is that list, ready to pass into Config.

Dangerous tools and preview

A tool marked dangerous = True gets a confirmation gate: before Agent runs it, it calls tool.preview(**arguments) and passes the result to the confirm hook. If confirm returns False, the tool never runs and the model is told "User declined to run this tool."

preview() defaults to a repr of the arguments, but the built-in dangerous tools override it:

• write_file / edit_file / delete_file — a unified diff of what would change
• bash — the literal command line ($ ...)
• MCP tools — the call rendered as tool_name(arg=value, ...)

See Permission prompts for how the CLI renders this.

MCP tools

Tools don't have to be local Python code. pycodeloop.core.mcp.load_mcp_tools(server) connects to a Model Context Protocol server and returns its remote tools already wrapped as Tool instances — the agent can't tell an MCP tool from a local one. See MCP servers.

Skills

When skills discovery is on, Config appends a read_skill tool and lists every discovered skill in the system prompt, so the agent can pull one in on demand. See Skills.

Writing your own

See Custom tools.