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Card 532 of 9992026-08-31 issue

Observed arrival · 2026-08-31

MCP Tuner Tests the Prompts Hidden in Tool Descriptions

mcptuner.com Observed source
Editorial interest 84/100 Selection signal · not a rating of the site

A deterministic auditor and transparent proxy for checking MCP server metadata, schemas, and wire traffic.

Landing page captured for the 2026-08-31 issue.

Field notes

The audit mode evaluates MCP tool, prompt, and resource metadata against a 28-rule catalog over stdio or Streamable HTTP, with non-zero exits for Critical or High failures so results can gate a build. The displayed fleet scan covers five servers and estimates tool-list size using characters divided by four. A separate observe mode acts as a transparent JSON-RPC proxy, forwarding bytes unchanged while scrubbing secrets from JSONL logs.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

OpenPublic substance visible
PrettyNotable craft visible
ProPolished or operationally mature
NicheUnusually specific use

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Habitat Reduced to One Settee

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mcptuner.com

Landing page observed 2026-08-31. The live site may have changed.