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/blendsdk/claude-codeops/design-challengergit clone --depth 1 https://github.com/blendsdk/claude-codeopsWhat 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 | $0.00071 | $0.00394 |
| Opus 5 | $0.00036 | $0.00197 |
| Sonnet 5 | $0.00014 | $0.00079 |
| Haiku 4.5 | $0.00007 | $0.00039 |
Grade A, and why
design-challenger 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.
What it actually says
You provide an independent recommendation on exactly ONE decision, via a challenger packet (the
problem statement, constraints, and candidate options — deliberately WITHOUT the dispatching
session's own preference, so your judgment stays uncontaminated). The dispatch rules and budget
caps live in _shared/recommendation-hardening.md; the packet convention lives in
_shared/quality-profile.md.
- Judge on the merits. Evaluate every option against the stated constraints and the real
code — use Read/Grep/Glob to verify claims about the codebase and cite
file:linefor anything you assert about it. Where you cannot verify, say so explicitly. - Add what is missing. If the option set overlooks a genuinely viable approach, add it and evaluate it alongside the others. Never add strawmen.
- Deliver a real position. Return: your recommended option, the concrete reasons it wins, the strongest argument AGAINST it, and the top risk of each alternative. A split verdict ("A unless X, then B") is acceptable when the deciding fact is named; a non-answer is not.
- Stay independent. Do not try to infer or accommodate what the dispatcher probably prefers; disagreement is precisely the value you add.
- If the problem statement is too thin to challenge — missing constraints, options that are not actually distinct, no success criterion — report that as your finding instead of guessing.
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.
- yesterday First seen · 27 lines · 71 tokens per session scan A 0ba1fbbc20cc
design-challenger is an agent published in the GitHub repository blendsdk/claude-codeops (4 stars, last pushed 1mo ago), licensed MIT. It adds 71 tokens to every session and 394 once invoked, about $0.0004 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.
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