GDAL MCP

# ADR-0008-error-handling-and-safety.md ## Title Error handling, masking, and tool safety annotations ## Status Proposed ## Context We need user-safe errors and clear risk signaling in MCP UIs. ## Decision * Initialize FastMCP with `mask_error_details=True`. * Raise `ToolError("human message")` for expected failures; let unexpected exceptions be masked. * Use annotations: `readOnlyHint` for info/VRT tools; `destructiveHint` only when writing; `idempotentHint` where applicable. ## Consequences * Pro: Safer UX; predictable error semantics; clearer consent surfaces. * Con: Must be disciplined about distinguishing expected vs unexpected errors.