test-skills

A validation command for checking the code and structure of LangChain-related skill documents. It looks for invalid Python, outdated imports, missing sections, and listed design problems.

In plain words
What is it for?
Use it to check one skill, all skills, or run a quick pass/fail overview, then review the reported fixes.
Why use it?
It helps find mistakes and warnings before a skill is used by an agent or shared with others.

Command

Install

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.

agentmods
npx agentmods add commands/codeblockz/langchain-community-plugin/test-skills
Clone the repo
git clone --depth 1 https://github.com/Codeblockz/langchain-community-plugin
Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 359 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00020 $0.00359
Opus 5 $0.00010 $0.00179
Sonnet 5 $0.00004 $0.00072
Haiku 4.5 $0.00002 $0.00036

Measured 2d ago against content hash a9c7aa1b72ad, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-skills 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 2d 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.

commands/test-skills.md · 70 lines

What it actually says

Test Skills Command

Validate skill content for correctness.

What It Checks

  1. Python syntax - Are code blocks valid Python?
  2. Anti-patterns - Using Pydantic for state? Missing checkpointer?
  3. Deprecated APIs - Using old import paths?
  4. Import paths - Do imports exist in current LangChain?
  5. Structure - Has Critical Rules and Common Gotchas sections?

Workflow

Step 1: Ask what to validate

What would you like to validate?
1. All skills
2. langgraph
3. langchain-rag
4. langchain-chains

Step 2: Run validation

cd ${CLAUDE_PLUGIN_ROOT}/..
python -m testing.cli validate --skill <selected>
# or
python -m testing.cli validate --all

Step 3: Show results

Report any errors or warnings found, with suggestions for fixes.

Quick Check

For a fast pass/fail overview:

python -m testing.cli quick

Example Output

============================================================
Skill: langgraph
============================================================
Code blocks checked: 8
Status: PASSED (2 warnings)

Issues:
  [WARN] [block 3, line 5] Code contains TODO/FIXME placeholder
          Rule: code/placeholder-todo
  [WARN] Skill should have a 'Common Gotchas' section
          Rule: structure/missing-gotchas
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. 2d ago First seen · 70 lines · 20 tokens per session scan A a9c7aa1b72ad

Subscribe to this mod's changes

test-skills is a command published in the GitHub repository Codeblockz/langchain-community-plugin (3 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 20 tokens to every session and 359 once invoked, about $0.0001 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.