Borrowing it
Nothing to install: this file belongs to Txpple/fvtt-mcp-molten5e. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Txpple/fvtt-mcp-molten5e/main/.claude/skills/bestiary-builder/SKILL.mdgit clone --depth 1 https://github.com/Txpple/fvtt-mcp-molten5eWrote 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/txpple/fvtt-mcp-molten5e/bestiary-builder)<a href="https://agentmods.dev/skills/txpple/fvtt-mcp-molten5e/bestiary-builder"><img src="https://agentmods.dev/badge/skills/txpple/fvtt-mcp-molten5e/bestiary-builder/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/txpple/fvtt-mcp-molten5e/bestiary-builder"><img src="https://agentmods.dev/badge/skills/txpple/fvtt-mcp-molten5e/bestiary-builder.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 | $0.00194 | $0.01658 |
| Opus 5.5 | $0.00078 | $0.00663 |
| Sonnet 5.5 | $0.00039 | $0.00332 |
| Haiku 4.5 | $0.00019 | $0.00166 |
Grade A, and why
bestiary-builder 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 — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Bestiary builder
The Bestiary is one journal — Bestiary, in the Adventure Log folder — with one page per
creature, alphabetical. Players can open it; it is how they learn what they just fought.
The deterministic half is the bundled script bestiary-entry.mjs (next to this file). There is no
MCP tool for this: reading a compendium journal page and setting entry-level journal ownership
both sit outside the tool surface, so the script drives the live session directly through
dist/foundry.js. Everything else — upload-asset, list-journals,
set-journal-page-visibility — is normal tooling.
Step 0 — Has it been earned?
The house rule: a page goes in after the party has fought the thing, not when the DM statted it. The bestiary is the players' trophy shelf and their reference; it must never front-run an encounter.
- Killed it → add it, player-visible.
- Fought it and it got away (the will-o'-wisp) → still add it; they met it and paid for the knowledge.
- Only glimpsed / heard rumored → ask the DM before adding.
- Prepped for a future session (the displacer beasts) → add it with
--gm-onlyif the DM wants it staged, and reveal it later withset-journal-page-visibility.
If a session recap is the source, work from the campaign repo's sessions/<date>/recap.md — it names
every creature that took a turn.
Step 1 — Resolve the real creature
Compendium-first, premium books only (design.md §2.3 — never the SRD). Name it as the Monster Manual names it:
- Shared lore is normal. The MM writes one narrative for a family: Hobgoblin Warrior, Captain and Warlord all point at Hobgoblins; Twig/Vine/Needle/Tree Blight all point at Blights. Pass any variant and the script lands on the shared page — so a party that fought both twig and vine blights gets one "Blights" page, not two. Re-running for the second variant just refreshes it.
- Use
--pagewhen the family name should win.--monster "Hobgoblin Warrior" --page "Hobgoblins"titles the page for the family rather than the one variant they killed. - Reskins and masked identities. A world NPC may be a reskin of an MM creature (or wear a
trueNamemask). Resolve to the true MM creature for the lore, but do not title the page with a name the players haven't earned — if they only know it as "the thing in the webs", ask the DM what to call it. - Not in the Monster Manual (homebrew, a Ravenloft/adventure-pack creature, a custom NPC): the
script exits with
not in the Monster Manualorno lore embed in its biography. Stop and ask the DM for the narrative — never invent monster lore, and never paste a stat block. Then build the page by hand withcreate-journal/update-journalin the same house shape, or run with--no-artand edit the text in after.
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.
- 2mo ago First seen · 113 lines · 194 tokens per session scan A 7fca2f393024
bestiary-builder is a skill published in the GitHub repository Txpple/fvtt-mcp-molten5e (0 stars, last pushed 1mo ago), licensed MIT. It adds 194 tokens to every session and 1,658 once invoked, about $0.0008 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.
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|---|---|---|---|---|---|---|---|
| bestiary-builderTxpple/fvtt-mcp-molten5e | Skill | 0 | 1mo ago | MIT | A | 194 | Claude Code |
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