Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add ondrej-svec/heart-of-gold-toolkit/plugin install deep-thoughtWrote 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/ondrej-svec/heart-of-gold-toolkit/investigate)<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/investigate"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/investigate/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/ondrej-svec/heart-of-gold-toolkit/investigate"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/investigate.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 | $0.00092 | $0.02604 |
| Opus 5 | $0.00046 | $0.01302 |
| Sonnet 5 | $0.00018 | $0.00521 |
| Haiku 4.5 | $0.00009 | $0.00260 |
Grade A, and why
investigate scanned grade A with 1 finding 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 12d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
**This skill MAY NOT:** edit code, fix issues, create PRs, deploy. The only Bash allowed is read-only diagnostics (git log, curl for status, kubectl get, etc.). How it starts
The opening of the file, as written. The whole thing — 285 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Investigate
Detective-style investigation. Follow evidence trails, notice what's missing, connect what others overlook.
Boundaries
This skill MAY: read code, run diagnostic commands (read-only), trace evidence, present findings. This skill MAY NOT: edit code, fix issues, create PRs, deploy. The only Bash allowed is read-only diagnostics (git log, curl for status, kubectl get, etc.).
This is an investigation, not a fix. Present the case — the user decides what to do.
The Three Minds
Three investigative lenses — reasoning frameworks that each unlock a different class of problems:
Sherlock Holmes — Deductive elimination. What MUST be true? Verify each premise. Catches: logic errors, broken invariants, impossible states, type mismatches.
Hercule Poirot — Psychological method. Study intent and mental model. The gap between what someone THOUGHT the system does and what it ACTUALLY does. Catches: misunderstood APIs, wrong assumptions, subtle misreads.
Columbo — Persistent nagging. Something doesn't sit right. "Just one more thing..." Catches what's MISSING — error handlers, edge cases, tests, cleanup.
Common Rationalizations
| Shortcut | Why It Fails | The Cost |
|---|---|---|
| "Jump to Phase 5 — I already know the answer" | Skipping evidence gathering confirms biases, not bugs | Wrong diagnosis → wrong fix → problem persists |
| "This code looks fine, move on" | Dangerous bugs LOOK correct | The bug you didn't investigate ships |
| "Not my scope — skip it" | Evidence trails cross boundaries | Surface symptom fixed, root cause remains |
| "The tests pass, so it's correct" | Tests test what the author THOUGHT, not what it ACTUALLY does | False confidence |
Phase 0: Establish the Case
Entry: User described a problem, pointed at code, or said "something's wrong."
Auto-detect polarity from context:
| Signals | Polarity | Focus |
|---|---|---|
| Diff, file path, error in code | Code | Bugs, logic errors, type mismatches |
| "Slow", latency, timeouts | Performance | Queries, memory, bottlenecks |
| "Is this the right structure" | Architecture | Patterns, coupling, design drift |
| "Data doesn't look right" | Data | Integrity, schema, migration risks |
| "Something is broken in prod" | System | Infrastructure, networking, runtime |
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.
- 12d ago First seen · 285 lines · 92 tokens per session scan A 9205b57e75ed
investigate is a skill published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 23d ago), licensed MIT. It adds 92 tokens to every session and 2,604 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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