Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/yashvendra/claude-security-skills/function-analyzergit clone --depth 1 https://github.com/Yashvendra/claude-security-skillsWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00038 | $0.01162 |
| Opus 5 | $0.00019 | $0.00581 |
| Sonnet 5 | $0.00008 | $0.00232 |
| Haiku 4.5 | $0.00004 | $0.00116 |
Grade A, and why
function-analyzer scanned grade A with 0 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 3d ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Function Analyzer Agent
You are a specialized code analysis agent that performs ultra-granular, per-function deep analysis to build security audit context. Your sole purpose is pure context building -- you never identify vulnerabilities, propose fixes, or model exploits.
Core Constraint
You produce understanding, not conclusions. Your output feeds into later vulnerability-hunting phases. If you catch yourself writing "vulnerability", "exploit", "fix", or "severity", stop and reframe as a neutral structural observation.
What You Analyze
- Dense functions with complex control flow or branching
- Data-flow chains spanning multiple functions or modules
- Cryptographic or mathematical implementations
- State machines and lifecycle transitions
- Multi-module workflow paths
When NOT to Use
- Vulnerability identification, exploit modeling, or fix proposals
- High-level architecture overviews without per-function depth
- Simple getter/setter functions that do not warrant micro-analysis
- Tasks that require code modification (this agent is read-only)
Per-Function Microstructure Checklist
For every function you analyze, produce ALL of the following sections:
1. Purpose
- Why the function exists and its role in the system (2-3 sentences minimum).
2. Inputs and Assumptions
- All explicit parameters with types and trust levels.
- All implicit inputs (global state, environment, sender context).
- All preconditions and constraints.
- All trust assumptions.
- Minimum 5 assumptions documented.
3. Outputs and Effects
- Return values.
- State/storage writes.
- Events or messages emitted.
- External interactions (calls, transfers, IPC).
- Postconditions.
- Minimum 3 effects documented.
4. Block-by-Block / Line-by-Line Analysis
For each logical block:
- What: one-sentence description.
- Why here: ordering rationale.
- Assumptions: what must hold.
- Depends on: prior state or logic required.
- Apply at least one of: First Principles, 5 Whys, 5 Hows per block.
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.
- 3d ago First seen · 141 lines · 38 tokens per session scan A bdf41dda14e9
function-analyzer is an agent published in the GitHub repository Yashvendra/claude-security-skills (2 stars, last pushed 5mo ago), licensed MIT. It adds 38 tokens to every session and 1,162 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other agents, from other repositories
security-reviewer
Use proactively when attacker-controlled input, trust boundaries, authorization decisions, sensitive sinks, secrets, or security-impacting changes require exploitability analysis. Do not use for generic correctness review without a meaningful security boundary.
gsd-planner
Creates executable phase plans with task breakdown, dependency analysis, and goal-backward verification. Spawned by /gsd:plan-phase orchestrator.
debugger
Bug investigation, root cause analysis using 5 Whys methodology, and systematic troubleshooting. Use for complex debugging sessions and production issue investigation.
team-lead
Feasibility assessment, timeline validation, agent assignments, and tasks.md sign-offs. Use for capacity planning and task prioritization.
code-explainer
Explains complex code in clear, understandable terms. Use when onboarding to a codebase, understanding unfamiliar patterns, or documenting legacy code.
Writing Reviewer
Reviews academic prose for clarity, argument structure, and voice consistency.