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 skills add bostonaholic/team --skill principle-never-interpolategit clone --depth 1 https://github.com/bostonaholic/teamWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/bostonaholic/team/principle-never-interpolate)<a href="https://agentmods.dev/skills/bostonaholic/team/principle-never-interpolate"><img src="https://agentmods.dev/badge/skills/bostonaholic/team/principle-never-interpolate/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/bostonaholic/team/principle-never-interpolate"><img src="https://agentmods.dev/badge/skills/bostonaholic/team/principle-never-interpolate.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00027 | $0.00269 |
| Opus 5 | $0.00014 | $0.00134 |
| Sonnet 5 | $0.00005 | $0.00054 |
| Haiku 4.5 | $0.00003 | $0.00027 |
Grade A, and why
principle-never-interpolate 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 4d 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.
What it actually says
Never Interpolate
Never place untrusted prose in shell command text; pass it by file (--body-file, -F body=@-), stdin, or environment into an unchanged declared command.
- Do not trust quoting: double quotes still execute
$(...)and backticks; heredoc delimiter lines end the heredoc and expose remaining text to the shell. - Put only same-invocation, byte-exact allowlisted scalars or guarded
"${VAR:?}"expansions into command text. - Validate branch names and IDs with
LC_ALL=Ccharacter allowlists; refuse failures without normalization. Syntax checkers do not make shell input safe. - Terminate options with
--unless position fixes the value's role and its allowlist forbids leading-. - Before destructive path use, require containment under the expected root, no
.., and no symlink. - Capture, validate, and use in the SAME invocation because shell state does not persist.
- Expand destructive or gate inputs as
"${VAR:?}"; before command substitution, guard consumed values with standalone: "${VAR:?}".
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 4d ago Changed · -22 lines · -25 tokens per session 8cd9f2d497da
- 6d ago First seen · 40 lines · 52 tokens per session scan A 1288b93d2207
principle-never-interpolate is a skill published in the GitHub repository bostonaholic/team (11 stars, last pushed today), licensed MIT. It adds 27 tokens to every session and 269 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 2026-09-03.
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