rohitg00/ai-engineering-from-scratch · error · KeyError

unknown tool {name!r}

Error message

unknown tool {name!r}

What it means

Error "unknown tool {name!r}" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/19-capstone-projects/21-tool-registry-schema-validation/code/main.py:96

        override: bool = False,
    ) -> ToolRecord:
        if not self._NAME_RE.match(name):
            raise ValueError(f"tool name {name!r} must match {self._NAME_RE.pattern}")
        if name in self._records and not override:
            raise ValueError(f"tool {name!r} already registered; pass override=True to replace")
        validate_schema_shape(schema)
        rec = ToolRecord(
            name=name, description=description, schema=schema, handler=handler,
            idempotent=idempotent, timeout_ms=timeout_ms,
        )
        if name not in self._records:
            self._order.append(name)
        self._records[name] = rec
        return rec

    def get(self, name: str) -> ToolRecord:
        if name not in self._records:
            raise KeyError(f"unknown tool {name!r}")
        return self._records[name]

    def names(self) -> list[str]:
        return list(self._order)

    def validate(self, name: str, args: Any) -> Ok | list[ValidationError]:
        rec = self.get(name)
        errors: list[ValidationError] = []
        _walk(rec.schema, args, "", errors)
        if errors:
            return errors
        return Ok()


def validate_schema_shape(schema: dict) -> None:
    """Reject schemas using keywords outside the supported subset."""
    if not isinstance(schema, dict):
        raise ValueError("schema must be a dict")

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/19-capstone-projects/21-tool-registry-schema-validation/code/main.py:96 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/dddc2c4c04c5572a. Report an issue: GitHub.