mcp-proof / effect evidence

@modelcontextprotocol/server-memory@2026.8.31 (case study)

no effect-conformance failures observed

Observation boundary. Effects are read out-of-band via an out-of-band parse of the JSONL store into per-entity/per-relation objects (TableStateObserver adapter, ~20 lines), never from the tools' own responses. Authority and effectiveness come from a probe that exercises created objects: none — this service mints no credential-like object with a local authorization rule to exercise, so authority/effectiveness stay unknown and EFF-06 SKIPs (probe-backed classification remains validated on the controlled testbed, E2/E3). Dimensions no channel can establish are marked unknown and their checks SKIP — never a silent pass. This is a controlled measurement instrument; findings here are about the audited server, not production prevalence.

Calls observed10

Authority objects0

Effect-conformance checks

Check	Level	Result	Details
EFF-01	MUST	✓ PASS	readOnlyHint is honoured (no observed external write) 3 readOnly-annotated tool call(s) caused no observed external write
EFF-02	MUST	✓ PASS	observed deletes are consistent with destructiveHint (explicit false contradicted ⇒ fail; unset ⇒ spec default true) all 2 observed deleted object(s) consistent with declared/default destructive semantics: 2 call(s) from tools declaring destructiveHint=true
EFF-03	SHOULD	✓ PASS	idempotentHint is honoured (a repeated identical call is a no-op) 1 repeated idempotent call(s) left external state unchanged
EFF-06	SHOULD	– SKIP	created authority does not outlive its authorizing grant no created authority-bearing object to assess

Per-call effect ledger

Declared annotations beside the effect an independent observer saw, the response a response-only auditor would have read, the objects that resulted, and the probe's authority / dependency verdict.

Call	Declared	Observed effect	Response seen	Objects / persistence	Authority (probed)	Lineage
create_entities {"entities": [{"name": "ada", "entityType": "person", "observations": ["studies delegated authority"]}, {"name": "mcp-proof", "entityType": "project", "observations": ["audits MCP servers"]}]}	readOnlyHint=False, destructiveHint=False, idempotentHint=False, openWorldHint=False	create observed observed 2 change(s): create entities/ada, create entities/mcp-proof	[ { "name": "ada", "entityType": "person", …	create entities/ada, create entities/mcp-proof ephemeral	unknown unknown probe inconclusive	by: — needs: —
create_relations {"relations": [{"from": "ada", "to": "mcp-proof", "relationType": "maintains"}]}	readOnlyHint=False, destructiveHint=False, idempotentHint=False, openWorldHint=False	create observed observed 1 change(s): create relations/ada→maintains→mcp-proof	[ { "from": "ada", "to": "mcp-proof", "rela…	create relations/ada→maintains→mcp-proof ephemeral	unknown unknown probe inconclusive	by: — needs: —
add_observations {"observations": [{"entityName": "ada", "contents": ["probes tool-created authority"]}]}	readOnlyHint=False, destructiveHint=False, idempotentHint=False, openWorldHint=False	update observed observed 1 change(s): update entities/ada	[ { "entityName": "ada", "addedObservations": […	update entities/ada —	not authority observed call created no object to bear authority	by: — needs: —
read_graph {}	readOnlyHint=True, destructiveHint=False, idempotentHint=True, openWorldHint=False	none observed no external object changed between before/after snapshots	{ "entities": [ { "name": "ada", "entit…	— —	not authority observed no object created	by: — needs: —
search_nodes {"query": "delegated"}	readOnlyHint=True, destructiveHint=False, idempotentHint=True, openWorldHint=False	none observed no external object changed between before/after snapshots	{ "entities": [ { "name": "ada", "entit…	— —	not authority observed no object created	by: — needs: —
open_nodes {"names": ["ada"]}	readOnlyHint=True, destructiveHint=False, idempotentHint=True, openWorldHint=False	none observed no external object changed between before/after snapshots	{ "entities": [ { "name": "ada", "entit…	— —	not authority observed no object created	by: — needs: —
delete_observations {"deletions": [{"entityName": "ada", "observations": ["probes tool-created authority"]}]}	readOnlyHint=False, destructiveHint=True, idempotentHint=True, openWorldHint=False	update observed observed 1 change(s): update entities/ada	Observations deleted successfully	update entities/ada —	not authority observed call created no object to bear authority	by: — needs: —
delete_relations {"relations": [{"from": "ada", "to": "mcp-proof", "relationType": "maintains"}]}	readOnlyHint=False, destructiveHint=True, idempotentHint=True, openWorldHint=False	delete observed observed 1 change(s): delete relations/ada→maintains→mcp-proof	Relations deleted successfully	delete relations/ada→maintains→mcp-proof —	not authority observed call created no object to bear authority	by: — needs: —
delete_entities {"entityNames": ["mcp-proof"]}	readOnlyHint=False, destructiveHint=True, idempotentHint=True, openWorldHint=False	delete observed observed 1 change(s): delete entities/mcp-proof	Entities deleted successfully	delete entities/mcp-proof —	not authority observed call created no object to bear authority	by: — needs: —
delete_entities {"entityNames": ["mcp-proof"]}	readOnlyHint=False, destructiveHint=True, idempotentHint=True, openWorldHint=False	none observed no external object changed between before/after snapshots	Entities deleted successfully	— —	not authority observed no object created	by: — needs: —