tool-use-and-function-calling skillA
tool-use-and-function-calling is agent-read markdown (skill) from jnpiyush/agentx: 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..
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns 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@v1.0.0mdr add jnpiyush/agentx/tool-use-and-function-calling@sha256:eae651b6a809a57bPin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
[](https://markdownregistry.com/a/art_63dctarpo7njiigf)
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Versions
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.0.0 latest | 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 (5528 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 · 16 stars · license Apache-2.0 · pushed 2026-09-21 · 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/eae651b6a809a57b7f62a6a0a51f5c456442f47f4ab5ec413bf92b43df68d6d2
Your agent 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.