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 umbraco/Umbraco-MCP-Base/plugin install umbraco-mcp-skillsWrote 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/umbraco/umbraco-mcp-base/build-tools)<a href="https://agentmods.dev/skills/umbraco/umbraco-mcp-base/build-tools"><img src="https://agentmods.dev/badge/skills/umbraco/umbraco-mcp-base/build-tools/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/umbraco/umbraco-mcp-base/build-tools"><img src="https://agentmods.dev/badge/skills/umbraco/umbraco-mcp-base/build-tools.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 | $0.00043 | $0.02424 |
| Opus 5.5 | $0.00017 | $0.00970 |
| Sonnet 5.5 | $0.00009 | $0.00485 |
| Haiku 4.5 | $0.00004 | $0.00242 |
Grade C, and why
build-tools 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 today.
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.
curl -fsSk "{swaggerUrl}" | node ${CLAUDE_PLUGIN_ROOT}/skills/build-tools/scripts/list-operations.ts {collection} Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -fsSk "{swaggerUrl}" | node ${CLAUDE_PLUGIN_ROOT}/skills/build-tools/scripts/list-operations.ts {collection} How it starts
The opening of the file, as written. The whole thing — 259 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Build Tools
Generate MCP tool collections from the API groups selected during discovery. This skill reads .discover.json and the swagger spec, then builds tool files one collection at a time.
IMPORTANT: This skill ONLY creates tool files, collection indexes, and registrations. Do NOT create any test files, test setup, test builders, test helpers, or __tests__/ directories. Testing is handled separately by the /build-tools-tests skill.
Prerequisites
Before running, ensure:
- You have run
npx @umbraco-cms/create-umbraco-mcp-server discover(.discover.jsonexists) - The API client has been generated (
src/umbraco-api/api/generated/directory exists — if not, runnpm run generate)
Arguments
- No arguments: build all collections from
.discover.json - Single collection name: build only that collection (e.g.
/build-tools form)
Agents
This skill orchestrates the following agents — use them for the relevant steps:
| Agent | When to use |
|---|---|
mcp-tool-creator |
Creating each tool file (Step 3b) |
mcp-tool-description-writer |
Writing tool descriptions (Step 3b) |
mcp-tool-reviewer |
Reviewing tools for LLM-readiness (Step 4) |
Workflow
Process one collection at a time. Complete each collection fully before starting the next.
Step 0: Read Discovery Manifest
Read .discover.json from the project root:
{
"apiName": "Umbraco Forms Management API",
"swaggerUrl": "https://localhost:44324/umbraco/swagger/forms-management/swagger.json",
"baseUrl": "https://localhost:44324",
"collections": ["form", "form-template", "field-type", "folder"]
}
If an argument was provided, filter to only that collection. If .discover.json doesn't exist, tell the user to run npx @umbraco-cms/create-umbraco-mcp-server discover first.
Step 1: Check Generated Client
Check if src/umbraco-api/api/generated/ exists and contains .ts files. If not, run:
npm run generate
Then read the generated files to understand:
- The API client function name (e.g.
getFormsManagementAPI) - The available Zod schemas (in
*.zod.tsfiles) - The available client methods and their signatures
What ships with it
2 files 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.
- today Changed · +11 lines scan A → C 2514732ba214
- 2mo ago First seen · 248 lines · 43 tokens per session scan A d76e13bcb479
build-tools is a skill published in the GitHub repository umbraco/Umbraco-MCP-Base (2 stars, last pushed yesterday), licensed MIT. It adds 43 tokens to every session and 2,424 once invoked, about $0.0002 per session on Opus 5.5. 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.
build-tools compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| build-toolsumbraco/Umbraco-MCP-Base | Skill | 2 | yesterday | MIT | C | 43 | Claude Code |
| mcp-tool-developersickn33/agentic-awesome-skills | Skill | 50k | yesterday | MIT | A | 38 | Claude Code |
| mem0-oss-to-platformmem0ai/mem0 | Skill | 69k | 7d ago | Apache-2.0 | A | 217 | Claude Code, Codex |
| azure-mgmt-botservice-dotnetmicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 78 | Claude Code |
| fastapi-router-pymicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 46 | Claude Code |
| dev-runtimelangwatch/langwatch | Skill | 5.0k | today | Apache-2.0 | A | 172 | Claude Code |
| api-designericrisco/rsc-harness | Skill | 598 | yesterday | MIT | A | 105 | Claude Code, Codex |