## Summary
- Add shared span attributes for tool error diagnostics, including
developer-facing messages when present.
- Wire those attributes through MCP server, worker RunTool, and HTTP
CallTool spans while keeping default MCP response content public-only.
- Cover no-leak response behavior, non-recording spans, outputless
worker responses, and the shared attribute contract.
## Verification
- `uv run ruff format ...`
- `uv run ruff check ...`
- `uv run pytest -W ignore
libs/tests/arcade_mcp_server/test_debug_exposure_integration.py
libs/tests/core/test_log_extras.py
libs/tests/worker/test_worker_base.py`
Made with [Cursor](https://cursor.com)
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Adds new telemetry attributes that propagate tool error messages
(including optional developer_message) into active spans across MCP
server and worker execution paths; risk is mainly around potential
leakage of sensitive developer messages into tracing backends and
changes to observability contracts.
>
> **Overview**
> Adds a shared
`arcade_core.log_extras.build_tool_error_span_attributes()` helper and
wires it into tool error paths so the current OpenTelemetry span is
annotated with stable `tool_error_*` attributes (including
`developer_message` when present).
>
> MCP tool calls now record these span attributes on failure while
keeping default MCP response content sanitized, and `arcade-serve`
records the same attributes on both `RunTool` and HTTP `CallTool` spans
(handling `output=None`). Versions and dependency constraints are bumped
to consume the new core helper, with tests added/updated to lock the
span-attribute contract and verify behavior for non-recording spans and
no-leak responses.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
33a53991d72140a662152f508dc53e9b769b9f07. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
## Summary
- Improve tool call error messages across 4 libraries (arcade-core,
arcade-tdk, arcade-mcp-server, arcade-serve) so agents can self-correct
and Datadog can facet on structured fields
- Guard empty error messages, enrich input validation errors with
field-level detail, fix `@tool` decorator fallback formatting, surface
`additional_prompt_content` in MCP responses, and add structured log
extras for Datadog
- Addresses the 3 worst error patterns: generic "Error in tool input
deserialization", bare `KeyError` values, and empty `FatalToolError`
messages
**Linear:** TOO-627
**Plan:** `docs/plans/2026-04-08-improve-error-messages-handoff.md`
## Tasks
- [ ] Task 1: Guard empty error messages (arcade-core)
- [ ] Task 2: Enrich input validation error messages (arcade-core)
- [ ] Task 3: Improve `@tool` decorator error fallback (arcade-tdk)
- [ ] Task 4: Fix MCP agent-facing error response (arcade-mcp-server)
- [ ] Task 5: Add structured log extras in BaseWorker (arcade-serve)
- [ ] Task 6: Add structured log extras in MCP server
(arcade-mcp-server)
## Test plan
- [ ] Each task has dedicated unit tests verifying the new behavior
- [ ] `make test` passes after all tasks
- [ ] `make check` (ruff + mypy) passes
- [ ] Verify the 3 worst error patterns now produce actionable messages
🤖 Generated with [Claude Code](https://claude.com/claude-code)
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Touches cross-library error formatting and logging behavior used in
production tool execution paths; while mostly additive/guardrails, it
changes agent-visible messages and Datadog log facets, which could
impact client expectations and alerting.
>
> **Overview**
> Improves tool-call error handling across core/runtime, MCP transport,
worker transport, and the TDK to make agent-visible failures more
actionable while *reducing sensitive-data leakage*.
>
> In `arcade-core`, empty error messages now get placeholders,
`ToolOutputFactory.fail*` defaults blank messages, and input validation
errors are rewritten as field-level summaries that intentionally omit
rejected values (avoiding Pydantic echo of secrets). The `@tool`
fallback in `arcade-tdk` no longer surfaces `str(exception)` to agents;
it returns exception *type-only* in `message` while preserving full
detail in `developer_message`.
>
> Adds a shared `build_tool_error_log_extra` helper and updates
`arcade-serve` + `arcade-mcp-server` to emit consistent structured
WARNING logs (`error_*`, `tool_name`, optional toolkit/version) for
Datadog, while MCP error responses now append
`additional_prompt_content` and force `structuredContent=None` on
failures per spec. Includes extensive new tests and bumps package
versions (`arcade-core` 4.6.2, `arcade-tdk` 3.6.1, `arcade-mcp-server`
1.19.3, `arcade-serve` 3.2.3).
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
e5c7ebcaf56176cfbd8e6d1f2b6295352abd0ec0. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
<!-- CURSOR_SUMMARY -->
> [!NOTE]
> **Low Risk**
> Mostly CI/test and CLI output tweaks, plus a small refactor to reuse
existing subprocess termination logic; low risk with minor potential for
CI environment/version compatibility issues.
>
> **Overview**
> Expands CI coverage by adding Python `3.13` and `3.14` to the GitHub
Actions matrices (main tests, install test, and no-auth CLI
integration), and removes a redundant editable install step in the
no-auth workflow.
>
> Cleans up Windows subprocess handling by dropping
`arcade_cli.deploy._graceful_terminate` and calling the shared
`arcade_core.subprocess_utils.graceful_terminate_process` directly, with
corresponding test updates.
>
> Improves `arcade new` scaffolding guidance by printing numbered “Next
steps” with explicit stdio/HTTP run options, and adds/updates CLI tests
to assert this output. Also bumps package version to `1.11.2` and
tightens pre-commit `ruff` excludes (no longer excluding `_scratch`).
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
55c2ae106f13e5657acdbebf63e00d74c171181f. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
### Overview
Major restructuring from monolithic `arcade-ai` package to modular
library architecture with standardized uv-based dependency management.

### New Package Structure
- **`arcade-tdk`** - Lightweight toolkit development kit (core
decorators, auth)
- **`arcade-core`** - Core execution engine and catalog functionality
- **`arcade-serve`** - FastAPI/MCP server components
- **`arcade-ai`** - Meta package that includes CLI functionality.
Optionally include evals via the `evals` extra. Optionally include all
packages via the `all` extra.
### Key Benefits
- **Lighter Dependencies**: Toolkits now depend only on `arcade-tdk` (~2
deps) vs full `arcade-ai` (~30+ deps)
- **Faster Builds**: uv provides 10-100x faster dependency resolution
and installation
- **Better Modularity**: Clear separation of concerns, consumers import
only what they need
- **Standard Tooling**: Eliminates custom poetry scripts, uses standard
Python packaging
### Migration Impact
- All 20 toolkits converted from poetry → uv with `arcade-tdk`
dependencies plus `arcade-ai[evals]` and `arcade-serve` dev
dependencies. When developing locally, devs should install toolkits via
`make install-local`.
- Modern Python 3.10+ type hints throughout
- Standardized build system with hatchling backend
- Enhanced Makefile with robust toolkit management commands
- Removed `arcade dev` CLI command
- Reduce the number of files created by `arcade new` and add an option
to not generate a tests and evals folder.
This foundation enables faster development cycles and cleaner dependency
chains for the growing toolkit ecosystem.
### Todo After this PR is merged
- [ ] Post-merge workflow(s) (release & publish containers, etc)
- [ ] Release order plan. @EricGustin suggests releasing in the
following order:
1. `arcade-core` version 0.1.0
2. `arcade-serve` version 0.1.0 and `arcade-tdk` version 0.1.0
3. `arcade-ai` version 2.0.0
4. Patch release for all toolkits (all changes in toolkits are internal
refactors)
- [ ] [Update docs](https://github.com/ArcadeAI/docs/pull/318)
---------
Co-authored-by: Eric Gustin <eric@arcade.dev>
Co-authored-by: Eric Gustin <34000337+EricGustin@users.noreply.github.com>
2025-06-11 16:48:17 -07:00
Renamed from arcade/tests/worker/test_worker_base.py (Browse further)