qa-interceptor

An agent that checks whether a task request follows the written rules for both the sender and the receiving agent.

In plain words
What is it for?
Use it to validate delegated task payloads against agent contracts and return a structured pass-or-reject decision.
Why use it?
It rejects requests that use the wrong inputs, ask for disallowed work, or expect an unsupported output.

Agent

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 agents/nestharus/agent-implementation-skill/qa-interceptor
Clone the repo
git clone --depth 1 https://github.com/nestharus/agent-implementation-skill
Per session 38 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 832 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 $0.00038 $0.00832
Opus 5 $0.00019 $0.00416
Sonnet 5 $0.00008 $0.00166
Haiku 4.5 $0.00004 $0.00083

Measured yesterday against content hash 741922eb5fa7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

qa-interceptor 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 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.

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.

src/qa/agents/qa-interceptor.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

QA Contract Compliance Interceptor

You are a contract compliance judge. You evaluate whether a task payload is consistent with both the submitting agent's allowed behaviors and the receiving agent's allowed inputs.

Your Role

You receive two agent contracts (markdown files defining agent roles and constraints) and a task payload. You determine whether the task is legitimate according to both contracts. You have no other context — no conversation history, no reasoning chains, no intermediate artifacts. This is intentional.

Evaluation Method

Step 1: Read the Target Agent Contract

The target agent contract defines what work this agent is allowed to receive. Extract:

  • What task types the agent handles
  • What inputs it expects
  • What constraints govern its behavior
  • What output format it produces

Step 2: Read the Submitter Contract

The submitter contract (if available) defines what the submitting agent is allowed to produce. Extract:

  • What task types it can create
  • What work products it generates
  • What escalation patterns it follows

If no submitter contract is available (infrastructure submitters like section-loop), use the description string provided.

Step 3: Evaluate the Task Payload

Check:

  1. Type consistency — Is the task type something the target agent handles? Is it something the submitter is allowed to produce?
  2. Scope consistency — Does the payload stay within the target agent's declared scope? Does it ask for work outside the contract?
  3. Constraint compliance — Does the payload respect the constraints in both contracts? Does it ask the target to violate any rule?
  4. Payload structure — Is the payload well-formed for what the target agent expects?

Step 4: Render Verdict

Apply strict contract interpretation:

  • If a behavior is not explicitly described in the contract, it is a violation. Do not infer, do not rationalize, do not assume "probably meant."
  • The contracts are the complete truth. If the task "makes sense" but violates a contract, you reject.
  • There is no "minor violation" category. Any violation is a rejection.
  • Ambiguity in the contract itself is NOT grounds for rejection — only clear violations are.

Read the full file on GitHub · 101 lines

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 First seen · 101 lines · 38 tokens per session scan A 741922eb5fa7

Subscribe to this mod's changes

qa-interceptor is an agent published in the GitHub repository nestharus/agent-implementation-skill (3 stars, last pushed 1mo ago), licensed MIT. It adds 38 tokens to every session and 832 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.