fix(agent-environment): sync MCP install script with template pins (#34)

[Abhishek21g]

Problem

mcp_server_template.json bumped @modelcontextprotocol/server-filesystem to 2026.7.10 but dev_scripts/install_mcp_packages.sh still installed @2025.11.25. Docker builds use the install script, so images could ship the broken pin — every directory_tree call fails MCP output validation (-32602) regardless of model (see #34, modelcontextprotocol/servers#3110).

Also drifted: duckduckgo-mcp-server (0.1.1 vs 0.5.0) and wikipedia-mcp (missing from install script).

Repro

cd services/agent-environment
python3 -m pytest tests/test_mcp_config_sync.py -v

Fails on main before this fix (NPX version mismatch on filesystem pin).

Fix

• Sync install_mcp_packages.sh to match template pins
• Add tests/test_filesystem_pin.py — minimum calver guard for filesystem server pinned to 2025.11.25 triggers directory_tree output-validation error (-32602) — fixed upstream in 2025.12.18+ #34
• Document pin policy in services/agent-environment/README.md

Verification

cd services/agent-environment
python3 -m pytest tests/ -v

Both test_package_sync and test_filesystem_pin_meets_minimum_for_directory_tree pass.

Greptile Summary

This PR syncs dev_scripts/install_mcp_packages.sh with mcp_server_template.json to fix a version drift that caused every directory_tree call to fail with MCP output validation error -32602 when using the @2025.11.25 filesystem server pin.

• Bumps @modelcontextprotocol/server-filesystem from 2025.11.25 to 2026.7.10, duckduckgo-mcp-server from 0.1.1 to 0.5.0, and adds wikipedia-mcp==2.0.1 to the install script.
• Adds tests/test_filesystem_pin.py as a regression guard enforcing the minimum CalVer pin, and documents the pin policy in README.md.

Confidence Score: 4/5

The version bump and sync are correct and well-guarded by two new tests; only minor polish issues remain.

The core changes — version pin updates and the new CalVer regression guard — address a real runtime breakage. The only findings are a redundant assertion, an upstream issue-number discrepancy in a docstring, and a missing trailing newline in the shell script, none of which affect runtime behavior.

The docstring in tests/test_filesystem_pin.py references a different upstream issue number than the PR description; worth a quick double-check before merge.

Important Files Changed

Filename	Overview
services/agent-environment/dev_scripts/install_mcp_packages.sh	Bumps filesystem server from 2025.11.25 to 2026.7.10, duckduckgo from 0.1.1 to 0.5.0, and adds wikipedia-mcp==2.0.1 to align with template pins; still missing trailing newline.
services/agent-environment/tests/test_filesystem_pin.py	New regression guard that reads the template JSON and verifies the filesystem CalVer pin meets the minimum; contains a logically redundant second assertion and an upstream issue-number discrepancy in its docstring.
services/agent-environment/README.md	Adds pin-policy documentation explaining the template-as-source-of-truth contract and the minimum filesystem version required to avoid -32602 errors.

Prompt To Fix All With AI

Fix the following 3 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 3
services/agent-environment/tests/test_filesystem_pin.py:50-56
The second assertion is logically redundant: if `calver >= MIN_FILESYSTEM_CALVER` (2025, 12, 18) passes, the result can never equal `KNOWN_BAD_FILESYSTEM_CALVER` (2025, 11, 25) since that value is strictly less than the minimum. The extra check adds noise without catching any additional cases.

```suggestion
    assert calver >= MIN_FILESYSTEM_CALVER, (
        f"filesystem pin {pin} is below minimum {MIN_FILESYSTEM_CALVER} "
        "(directory_tree MCP validation — see #34)"
    )
```

### Issue 2 of 3
services/agent-environment/tests/test_filesystem_pin.py:4-6
The PR description cites `modelcontextprotocol/servers#3110` as the upstream bug report, but the module docstring references `#3113`. These point to different issues — one of the two is wrong and will mislead anyone tracing the fix.

```suggestion
The filesystem MCP server @2025.11.25 returns structured content for
directory_tree that fails MCP output validation (-32602). Fixed upstream in
modelcontextprotocol/servers#3110 (2025.12.18+).
```

### Issue 3 of 3
services/agent-environment/dev_scripts/install_mcp_packages.sh:44
The file is still missing a trailing newline (the diff shows `\ No newline at end of file`). POSIX requires text files to end with a newline, and some tools (e.g. `cat`, `wc -l`) behave unexpectedly without one.

```suggestion
echo "All UVX/NPX MCP packages installation complete. Ignored any that install from github!"
```

_{Reviews (1): Last reviewed commit: "fix(agent-environment): sync MCP install..." | Re-trigger Greptile}

[kalyanamdewri]

Container-level directory_tree validation

Image sha256:bffc65f85555c35647b3e856c328f3da634e76fac364049d5e86e187ff1fd109 installed filesystem server 2026.7.10. Request hash sha256:b917460a753778d7dbab4d45d12e50c2d2ac7319c50b588ac1c151e947cf29ce returned JSON-RPC code none (success); schema validation PASSED at none.

Ref	Installed package	RPC result	Duration
main d01e9b590e931f877bc01565ab57d191603561f6	@modelcontextprotocol/server-filesystem@2026.7.10	success; schema and expected tree passed	0.002757 s
PR 9c0bc6098784093daf5c547fe9712ed99d31476e	@modelcontextprotocol/server-filesystem@2026.7.10	success; schema and expected tree passed	0.002833 s

Request, response, and image manifest: https://gist.github.com/kalyanamdewri/b21e64b90332b07c0004d9d7263d8b2d. This validates the built container only; I did not test other MCP tools, the HTTP /call-tool aggregation path, production-scale directory trees, or non-Docker deployments.

[geobio]

I couldn't directly push to this branch, but I took your changes into this new PR. Thanks @Abhishek21g !! #63