• SaaS SSE/HTTP servers for product data (e.g., docs, tickets)
  • Local stdio servers for CLIs/databases
  • Composite agents with multiple servers (fetch, search, storage)

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Multi‑server agents

Combine multiple servers on a single agent and constrain path with assertions: 
from mcp_eval.catalog import Expect

await session.assert_that(Expect.tools.sequence(["search", "fetch"]))
await session.assert_that(Expect.path.efficiency(expected_tool_sequence=["search","fetch"]))

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Server discovery and drift

  • Use mcp-eval server list -v in CI to detect missing tools.
  • Add an Expect.tools.count(tool, >=1) guard to ensure expected calls happen.

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Security

  • Store credentials in CI secrets / local secrets file.
  • Avoid writing secrets in mcp.json or DXT.