Observed arrival · 2026-08-24
EffectProbe measures what agent tools actually do
EffectProbe audits agent tool calls by marking arguments, observing where the values surface, and compiling the results into an enforceable contract.
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✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
Field notes
The method inserts a marked value into one tool argument at a time, executes the tool, and traces where that value surfaces. One homepage example reports 114 of 183 arguments in @antv/mcp-server-chart controlling the request payload while zero controlled the destination. Linked reports also cover firecrawl-mcp, @playwright/mcp, and godot-mcp-server, including cases where effects were withheld rather than attributed.
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○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
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