valid-with-arguments_skill

Overview

This skill implements argument substitution using a $ARGUMENTS placeholder to pass dynamic input into prompts and agent actions. It is designed for agents and prompt pipelines that need a simple, reliable way to inject runtime parameters. The skill is language-agnostic in concept and integrates easily with Python-based agents and frameworks like LangChain or Anthropic clients.

How this skill works

At runtime the skill replaces the $ARGUMENTS placeholder with the provided argument string or structured payload before sending the prompt to the model. It supports simple string substitution and can be extended to perform light escaping or formatting for JSON and YAML use. The substitution happens early in the pipeline so downstream tools and LLMs receive a fully resolved prompt.

When to use it

• You need to pass user input or context into a reusable prompt template.
• Building agent actions that accept variable parameters at invocation time.
• Testing prompt variants by swapping argument values programmatically.
• Composing multi-step workflows where later steps reference prior outputs as arguments.
• Integrating LLMs with external systems where commands include runtime data.

Best practices

• Validate and sanitize arguments before substitution to avoid injection issues.
• Keep placeholders predictable and document expected formats (string, JSON, etc.).
• Use structured serialization (JSON) when passing complex data to avoid parsing errors.
• Limit the size of substituted content to fit model token constraints.
• Add unit tests that cover edge cases like empty, null, or special-character arguments.

Example use cases

• Prompt templating: Replace $ARGUMENTS with a user question inside a reusable assistant prompt.
• Agent commands: Inject a file path or ID into an action that triggers external processing.
• Workflow chaining: Feed the output of step A into step B by substituting it into B's prompt.
• A/B testing: Swap different argument values to compare model responses to prompt variants.
• Tool integration: Pass API keys or request parameters securely via sanitized arguments for backend calls.