Stage 1 of 5. Read the project prerequisites before starting; this stage builds on the preceding contracts.
What changes
Create five narrowly scoped read operations for each of 50 resource kinds. The names and schemas are stable; execution reads an injected inventory rather than contacting a cluster. A tool schema defines the exact accepted keys and values, so an unknown argument never reaches a handler by accident.
Work through one concrete case
Fifty resource families times five operations produce 250 teaching tools, but all share one local inventory mechanism. A supplied inventory containing only pods exposes five useful resource tools; the composed server adds catalog_search as the sixth.
pj mcp at scale 1
Change the lab inputs and calculate the result before reading its metrics. The figure computes from those inputs; the implementation tests below remain the source of completion evidence.
Implement the contract
Implement registry.py: catalog, execute. This artifact is stage 1 of MCP Server With 250 Tools. It consumes explicit inputs and returns an inspectable result that the next stage can use.
Use the public API contract and the typed starter signatures. Return values from core functions and let the supplied driver own file input, argument parsing and presentation.
Keep public name, description and inputSchema separate from internal resource/operation metadata. Validate exact argument keys before consulting inventory.
Verify and inspect
From the repository root, initialize once with python3 scripts/project_test.py mcp-at-scale --init learning-artifacts/mcp-at-scale. Then grade cumulatively:
python3 scripts/project_test.py mcp-at-scale --stage 1 --path learning-artifacts/mcp-at-scale --strictA fresh workspace should fail until you implement the contract. After every stage is complete, run your actual artifact from the supplied sample:
cd learning-artifacts/mcp-at-scale
python3 cli.py samples/inventory.json --query "pods count" --max-chars 500Investigate the failure boundary
Pass {query:"worker",extra:true} to pods_search. It must fail rather than quietly ignoring an unrecognized instruction.