[P1] Lens silently rolls up aggregations to caller scope — same query returns per-foundation counts or zeros+TLF total with no warning

[seberslinux]

Summary

Lens silently changes aggregation behaviour based on the caller's scope. The same query, phrased two different ways, returns either correct per-foundation counts or all zeros plus one large TLF-level total — with no warning or indication that rollup occurred.

Observed behaviour

• Query A (per-foundation phrasing) → correct per-foundation counts
• Query B (equivalent intent, different phrasing) → all zeros + one aggregated TLF total

MCP returns aggregated values in cases where PCC holds per-foundation values. The caller has no way to know which behaviour they'll get.

Impact

Silent data corruption — callers receive wrong answers without any error or warning. Automation built on top of MCP can produce incorrect results without any indication of failure.

Location

Lens MCP — aggregation/scoping layer

Severity

P1 — silent incorrect results

Suggested fix

1. Make aggregation rollup behaviour explicit and documented.
2. Return a metadata field indicating whether the result is per-resource or rolled up.
3. Or raise an error when the query intent is ambiguous.

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Reported by Stephan Ebers — found while building NPS survey automation against the LFX APIs.