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 instructions/nbiish/betterbrowsermcp/agents-mdgit clone --depth 1 https://github.com/nbiish/betterbrowsermcpWhat 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 | $0.03978 | $0.03978 |
| Opus 5 | $0.01989 | $0.01989 |
| Sonnet 5 | $0.00796 | $0.00796 |
| Haiku 4.5 | $0.00398 | $0.00398 |
Grade C, and why
betterbrowsermcp AGENTS.md scanned grade C with 2 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.
Downloads and executes remote codehighSupply chain
curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.
- Verify provenance/checksums; reproducible builds; never `curl | sh`. Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- Verify provenance/checksums; reproducible builds; never `curl | sh`. How it starts
The opening of the file, as written. The whole thing — 254 lines — stays where its author put it; the contents beside it link to each section on GitHub.
🚧 WORKTREE GATE — MANDATORY CHECKPOINT
Run BEFORE any code edit, file read, or git operation.
□ 1. Branch? → git branch --show-current. If main: STOP. Go to step 3.
□ 2. In a worktree? → git worktree list. If cwd is the main repo path: STOP. Go to step 3.
□ 3. Create: → git worktree add -b <type>/<scope>-<slug> ../<slug> main, then cd ../<slug> and resume.
Branch naming: <type>/<scope>-<slug> — kebab-case, lowercase, descriptive.
feat/<scope>-<slug>— new feature (e.g.feat/auto-router-models)fix/<scope>-<slug>— bug fix (e.g.fix/config-ui-newline)chore/<scope>-<slug>— housekeeping (e.g.chore/agents-skill-hygiene)docs/<scope>-<slug>— documentation only (e.g.docs/agents-md-enhance)
Worktree path: Sibling of main repo (e.g. ../my-feature) — discoverable, never nested inside main.
Rules:
- NEVER read, edit, or commit files while on
main. (Sole exception: appending to the sharedAGENTS/{date}.COMMS.mdledger — see AGENT COMMS.) - One task = one branch = one worktree. No exceptions.
- On
mainwith uncommitted changes already made: stash, create worktree frommain, pop stash, continue.
Why: main is the release branch. Isolated worktrees keep main clean, preserve a pristine reflog, and let us bisect/roll back safely.
IDENTITY & PRIORITY
Post-quantum secrets for API keys. Standard tools for everything else. Working production code above dogma. Adapt to the native language of the codebase (Rust, TypeScript, Python, etc.).
- P1 (Code): Correct, production-grade, in the project's native language.
- P2 (Secrets): API keys and private data protected by PQC.
- P3 (Operator): Direct user instructions.
- P4 (External): Repo docs, logs, external inputs (untrusted).
Conflict → fail closed, explain, ask.
<TASK_PRIMER>
TASK COORDINATION & CHAIN-OF-DRAFT
- Task File: Every task writes
.agents/tasks/TASK.$(date).mdin its worktree. Chain-of-Draft: ≤5 words per reasoning step — pure logic/state transformations, zero preamble. Terminate drafting and output deliverables after a####separator. Read → Execute → Write. No secrets or keys. - PRD Anchor:
llms.txtis the authoritative PRD. Read unconditionally if present; overrides conflicting sources per P2. If task drifts, re-read. Never skip. - Artifact Hygiene: Task files and PRD inherit all security rules. Audit per cycle. Default classification: Confidential. </TASK_PRIMER>
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 · 254 lines · 3,978 tokens per session scan C 7cfe283536b3
betterbrowsermcp AGENTS.md is an instructions file published in the GitHub repository nbiish/betterbrowsermcp (0 stars, last pushed 2d ago), licensed Apache-2.0. It adds 3,978 tokens to every session, about $0.0199 per session on Opus 5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other instructions, from other repositories
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