MCP server metadata description exceeds safe length budget
Summary
MCP server whose tool-listing metadata includes a multi-thousand-character description crafted to saturate the agent's context budget and dilute the user's intended instructions. Quantity, not content, is the attack primitive.
Severity & confidence
Low
Hygiene-grade issue with limited direct impact. Fix opportunistically; monitor in case context changes (new exploit, new dependency, etc.).
Confirmed
Observed directly by Jiffy scanners or validated by multiple independent sources. Indicators are reliable enough to drive automated action.
Indicators
Observed patterns and artifacts associated with this entry. Each indicator can be copied into your detection stack or SIEM.
(?i)description\s*:\s*"[^"]{5000,}"
Detection rule
A YARA-style pseudo-rule auto-generated from the indicators above. Useful as a starting point — adapt the syntax for your target detection platform.
rule jiffy_ti_2026_000051
{
meta:
source = "jiffy-intel"
severity = "low"
description = "Auto-generated from Jiffy Intel indicators"
strings:
$content_pattern_0 = "(?i)description\\s*:\\s*\"[^\"]{5000,}\""
condition:
$content_pattern_0
}Auto-generated from the indicators above. Adapt syntax for your detection stack before deploying.
Affected tools
| Tool | Versions | Status |
|---|---|---|
| Any MCP-capable agent | * | vulnerable |
Example artifacts
Sanitized examples of artifacts Jiffy has observed exhibiting this pattern. Publisher handles are redacted; version ranges and status reflect the most recent scan.
- bloat-doc-mcpMCP serverUnder review
- verbose-docs-mcpMCP serverQuarantined
How to remediate
Cap MCP tool description length at 2000 chars at the agent runtime.
Timeline & sources
Timeline
- First observedMar 13, 20261 month ago
- Last updatedApr 24, 2026today
- PublishedMar 25, 202623 days ago
Sources
References
Scan for patterns like this
Point Jiffy at your GitHub org, IDE config, or a single artifact. Get a scored report in under a minute.
Start a free scan