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

ValidateSource() for arcadedb-execute-cypher asserts the bound source implements the tool's compatibleSource interface (an ArcadeDB HTTP-capable source). Any other source type fails with this error naming the tool type and source name.

Source

Thrown at internal/tools/arcadedb/arcadedbexecutecypher/arcadedbexecutecypher.go:152

	return resp, nil
}

func (t Tool) EmbedParams(ctx context.Context, paramValues parameters.ParamValues, pMgr tools.PrimitiveManagerI) (parameters.ParamValues, error) {
	return parameters.EmbedParams(ctx, t.StaticParameters, paramValues, pMgr, 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 an arcadedb source.
  2. Verify the source kind in the sources: section is arcadedb.
  3. If targeting another database, use that engine's execute-sql/cypher tool instead.
Defensive patterns

Strategy: type-guard

Validate before calling

if err := tool.ValidateSource(src); err != nil {
    return fmt.Errorf("arcadedb-execute-cypher bound to non-ArcadeDB source: %w", err)
}

Type guard

cs, ok := src.(arcadedbexecutecypher.CompatibleSource)
if !ok {
    return fmt.Errorf("source %T is not an ArcadeDB source", src)
}

Try / catch

if err := tool.ValidateSource(src); err != nil {
    return fmt.Errorf("source validation failed: %w", err)
}

Prevention

When it happens

Trigger: Attaching the cypher tool to a non-ArcadeDB source (e.g. postgres) and validating at startup, or passing a wrong source directly to ValidateSource.

Common situations: Copy-pasted tool configs referencing the wrong source name; source kind changed from arcadedb to something else while tools still point at it.

Related errors

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/546d9f70ffa870d9. Report an issue: GitHub.