googleapis/mcp-toolbox · error

invalid source for %q tool: source %q is not a compatible ty

Error message

invalid source for %q tool: source %q is not a compatible type

What it means

The modify-spec vector tool's ValidateSource guard rejected the configured source because it does not implement compatibleSource — the tool is bound to a source that is not a Cloud SQL for Postgres source (with pgvector).

Source

Thrown at internal/tools/cloudsqlpg/vectorassistmodifyspec/vectorassistmodifyspec.go:151

	resp, err := source.RunSQL(ctx, modifySpecQuery, []any{namedArgs})
	if err != nil {
		return nil, util.ProcessGeneralError(err)
	}
	return resp, nil
}

func (t Tool) GetSourceName() string {
	return t.Cfg.Source
}

func (t Tool) ToConfig() tools.ToolConfig {
	return t.Cfg
}

func (t Tool) ValidateSource(source sources.Source) error {
	_, ok := source.(compatibleSource)
	if !ok {
		return fmt.Errorf("invalid source for %q tool: source %q is not a compatible type", t.Cfg.Type, t.Cfg.Source)
	}
	return nil
}

View on GitHub (pinned to 8cc6e09de2)

Solutions

  1. Point the tool's `source` at a Cloud SQL for Postgres source
  2. Check the source name for typos
  3. Verify the source `type` matches what this tool requires
Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at internal/tools/cloudsqlpg/vectorassistmodifyspec/vectorassistmodifyspec.go:151 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/e55ac0b1026616fa. Report an issue: GitHub.