ai-agent-security

ai-agent-security is a skill for Claude Code from sickn33/agentic-awesome-skills. It costs 25 tokens per session (3,587 once invoked), scanned B, original, MIT.

A security guide for AI agents that addresses harmful instructions, unsafe tool use, data leaks, and excessive permissions. It presents layered controls for agents that receive input and take actions.

In plain words
What is it for?
Use it to build input checks, protected tool execution, permission boundaries, audit logs, output filtering, and controls against repeated tool calls or data exfiltration.
Why use it?
It helps defend against prompt injection, where untrusted text tries to change an agent's instructions, and against misuse of tools or stolen data.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python /tools/execute.py --tool="$TOOL_NAME" --args="$TOOL_ARGS".

Part of the agentic-awesome-skills plugin — 257 skills shipped together

Good fit Use it to build input checks, protected tool execution, permission boundaries, audit logs, output filtering, and controls against repeated tool calls or data exfiltration.

Compare 6 skills from other repositories ↓
About the project

AAS Core is a local control plane for coding agents that lets them search a large catalogue of skills, choose a stack, validate it, and create a reproducible plan. It is used to assemble and review agent workflows through its CLI, local MCP server, catalogue, plugins, and Workbench. The catalogue add-ons provide the skills, plugins, bundles, and workflows that AAS Core helps agents select and validate.

sickn33/agentic-awesome-skills · 48,503 stars · on GitHub · aaskills.tech

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills
agentmods
npx agentmods add skills/sickn33/agentic-awesome-skills/ai-agent-security

Made for: Claude Code.

Or install agentic-awesome-skills, the plugin that ships this one along with the rest of its 257 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ai-agent-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/ai-agent-security/github.svg)](https://agentmods.dev/skills/sickn33/agentic-awesome-skills/ai-agent-security)
Your own site
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/ai-agent-security"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/ai-agent-security/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ai-agent-security

Your own site · 80×15
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/ai-agent-security"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/ai-agent-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,587 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 3 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00025 $0.03587
Opus 5.5 $0.00010 $0.01435
Sonnet 5.5 $0.00005 $0.00717
Haiku 4.5 $0.00003 $0.00359

Measured yesterday against content hash e868427d541d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

ai-agent-security scanned grade B with 3 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Harvests environment variablesmediumData exfiltration

Enumerating or grepping the environment for keys collects credentials unrelated to what the mod says it does.

**Privilege Escalation** — The agent chains low-privilege tool calls to achieve high-privilege outcomes (e.g., read config -> extract credentials -> call admin API).

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Asks for rootlowPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

curl -fsSL https://gvisor.dev/archive.key | sudo gpg --dearmor -o /usr/share/keyrings/gvisor-archive-keyring.gpg

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

(r"(?:curl|wget|nc|ncat)\s+", "network_command_inject"),
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

plugins/agentic-awesome-skills-claude/skills/ai-agent-security/SKILL.md · 395 lines

How it starts

The opening of the file, as written. The whole thing — 395 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AI Agent Security

Protect agentic AI systems from adversarial input, unsafe tool execution, data leakage, and privilege abuse with layered security controls.

These are partial design sketches, not a working security boundary. Regexes/classifiers have false positives and false negatives; prompt text cannot grant permissions. Enforce tenant identity, resource scope and approved actions in the tool service using authenticated server-side context. Input signing authenticates origin, not the safety of signed content. Bind approvals to the exact operation/arguments and recheck immediately before execution. Test failure paths and concurrency before production use.

Prerequisites

  • Python 3.10+ for guardrail code examples
  • Docker or Podman for sandbox execution
  • OpenTelemetry collector for audit logging
  • Familiarity with your agent framework (LangChain, CrewAI, Autogen, custom)
  • Access to policy engine (OPA/Cedar) for permission boundaries

Threat Model — STRIDE for AI Agents

AI agents introduce a unique threat surface. Apply STRIDE specifically to agentic components:

Threat Agent-Specific Example Control
Spoofing Attacker crafts input that mimics a trusted internal tool response Signed tool responses, HMAC verification
Tampering Prompt injection modifies agent reasoning mid-chain Input validation, prompt armoring
Repudiation Agent takes destructive action with no audit trail Immutable structured logging
Information Disclosure Agent leaks PII, secrets, or internal architecture in responses Output filtering, content classifiers
Denial of Service Adversarial prompt causes infinite tool loops or token exhaustion Rate limits, token budgets, circuit breakers
Elevation of Privilege Agent escalates from read-only to write via chained tool calls RBAC per tool, least-privilege scoping

Key Threat Categories

Prompt Injection — Untrusted content (user input, web scrapes, document contents) manipulates the agent's system prompt or reasoning chain to execute unintended actions.

Read the full file on GitHub · 395 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday Changed · +1 lines e868427d541d
  2. 1mo ago First seen · 394 lines · 25 tokens per session scan B 66776bd8ae18

Subscribe to this mod's changes

ai-agent-security is a skill published in the GitHub repository sickn33/agentic-awesome-skills (48,503 stars, last pushed yesterday), licensed MIT. It adds 25 tokens to every session and 3,587 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it B with 3 findings (harvests environment variables, asks for root, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-21.