tool-use-and-function-calling SKILL.md skillA
tool-use-and-function-calling from jnpiyush/agentx is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jnpiyush/agentx/tool-use-and-function-calling@v1.0.0Pins v1.0.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jnpiyush/agentx
- Path
.github/skills/ai-systems/tool-use-and-function-calling/SKILL.md- Versions recorded
- 4
- Latest version
- v1.0.0, committed Oct 10, 2026
- First version recorded
- Apr 30, 2026
- Size
- 5,675 bytes
- Repository stars
- 19
- License
- Apache-2.0
Design robust tool-use and function-calling for LLM agents. Use when defining tool schemas (JSON Schema, OpenAPI), enabling parallel tool calls, structured outputs (JSON mode / response_format), tool error handling, retries, idempotency, and tool selection prompts. Covers OpenAI tools, Anthropic tool_use, Gemini function calling, and MCP tools.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Tool Use and Function Calling
> **Purpose**: Build LLM agents that call tools reliably with correct arguments, handle failures gracefully, and produce structured results.
---
## When to Use This Skill
- Designing tools / functions an agent will call
- Defining JSON schemas for tool arguments and structured outputs
- Enabling and tuning parallel tool calls
- Designing tool error contracts and retries
- Building MCP tools (see also `mcp-server-development`)
---
## Tool Design Principles
| Principle | Rule |
|-----------|------|
| Single responsibility | One tool = one verb-phrase action |
| Strict typing | JSON Schema with `required`, types, `enum`, `pattern` |
| Idempotent where possible | Safe to retry on transient failure |
| Stateless arguments | All inputs in args -- no hidden context |
| Bounded outputs | Cap response size; truncate large lists with pagination tokens |
| Errors as data | Return `{ ok: false, error: { code, message, retryable } }`, do not throw |
---
## Schema Quality Checklist
- [ ] `description` on every tool and every parameter
- [ ] `required` array lists ONLY truly required params
- [ ] Use `enum` for fixed value sets (not free-form strings)
…Read the whole file at its exact version.
How to install
mdr add jnpiyush/agentx/tool-use-and-function-calling@sha256:88a0ba68ebeed5a9The line at the top of this page pins the label v1.0.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_63dctarpo7njiigf)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Apr 30, 2026 and Oct 10, 2026, about one every 54 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.0.0 latest | 2026-10-10 | 87e53aa | 5,675 B | A | view · diff |
| v1.0.0 | 2026-09-15 | f17c505 | 5,528 B | A | view · diff |
| v1.0.0 | 2026-06-23 | bab3a1b | 5,526 B | A | view · diff |
| v1.0.0 | 2026-04-30 | 4f38ce8 | 5,531 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5675 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
jnpiyush/agentx · 19 stars · license Apache-2.0 · pushed 2026-11-04 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_63dctarpo7njiigf GET https://markdownregistry.com/api/v1/resolve?ref=jnpiyush/agentx/tool-use-and-function-calling GET https://markdownregistry.com/api/v1/blob/88a0ba68ebeed5a927e834077e92985ab6b87d0be4a4ef4a9277d6b0d6ac7edf
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.