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.
git clone --depth 1 https://github.com/gustavobarbosab/sageWrote 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/rules/gustavobarbosab/sage/sage-behavior)<a href="https://agentmods.dev/rules/gustavobarbosab/sage/sage-behavior"><img src="https://agentmods.dev/badge/rules/gustavobarbosab/sage/sage-behavior/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/rules/gustavobarbosab/sage/sage-behavior"><img src="https://agentmods.dev/badge/rules/gustavobarbosab/sage/sage-behavior.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 | $0.00013 | $0.00586 |
| Opus 5.5 | $0.00005 | $0.00234 |
| Sonnet 5.5 | $0.00003 | $0.00117 |
| Haiku 4.5 | $0.00001 | $0.00059 |
Grade A, and why
sage-behavior 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/sage behavior
Generates behavior.md from spec.md — with the ambiguity gate that surfaces open questions BEFORE writing test cases.
Note: When triggered via
/sage spec, this step runs automatically after spec.md is generated. Use/sage behaviordirectly only when you already have aspec.mdand want to regenerate behavior.md independently.
Instructions
Read spec.md and the harness. Then generate behavior.md in exactly this structure:
Section 1 — Open Questions (REQUIRED, always first)
Analyze spec.md and list every ambiguity, missing detail, or behavioral decision not explicitly covered. Format:
## Open Questions
- [ ] <Question about an ambiguous behavior>
- [ ] <Question about a missing edge case>
- [ ] <Question about a conflicting constraint>
Surface anything where:
- The spec is silent on expected behavior
- Two interpretations are equally valid
- An edge case isn't explicitly covered
- A constraint conflicts with another
If there are genuinely no ambiguities: - No open questions.
DO NOT skip this section under any circumstances.
Section 2 — Test Cases (BLOCKED until questions resolved)
If open questions exist:
## Test Cases
> ⚠️ Pending resolution of open questions above. Do not finalize.
STOP HERE. Wait for the user to resolve questions.
If NO open questions: generate full test cases immediately (see below).
Resolving open questions
The user will either:
- Answer questions inline in chat
- Mark each
[ ]as[x]with the answer in behavior.md - Update spec.md to remove the ambiguity
When all questions are resolved, finalize test cases.
Finalizing test cases
Group scenarios under: Happy path, Validation, Edge cases, Error handling.
For each scenario provide TWO versions:
**Scenario: <Short descriptive title>**
Short → <one-line condensed form: condition + action + outcome>
Full:
- Given <precondition>
- When <action>
- Then <expected outcome>
- And <additional assertion if needed>
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.
- 2mo ago First seen · 99 lines · 13 tokens per session scan A b0ef71e2584c
sage-behavior is a cursor rule published in the GitHub repository gustavobarbosab/sage (2 stars, last pushed 4mo ago), licensed MIT. It adds 13 tokens to every session and 586 once invoked, about $0.0001 per session on Opus 5.5. 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.
Other cursor rules, from other repositories
mcpnuke-tests
Test conventions for mcpnuke — enforces TDD workflow.
debug-issue
When the user reports a bug, an error, or unexpected behavior. Enforces four structured phases — reproduction, failing test, root cause isolation, fix and verify — to stop guess-and-check loops.
common-testing
Testing requirements: 80% coverage, TDD workflow.
testing_rules
A testing guide covering TDD, where tests are written before code, and BDD, where expected behavior is described in Given-When-Then form.
tdd
Test-driven development — red-green-refactor cycle.
testing-standards
testing guidelines and expectations.