Missing `title` and `arguments` fields in Prompt definition (spec compliance)

[vjik]

While working with the Prompt API, I noticed a discrepancy between the official MCP specification and the current PHP SDK implementation.

According to the Model Context Protocol Specification:

The prompt object supports the following optional fields:

• title: Optional human-readable name of the prompt for display purposes
• arguments: Optional list of arguments for prompt customization

However, these fields do not appear to be supported or exposed in the current PHP SDK.

Expected behavior

The PHP SDK should support:

• Defining a title for prompts
• Defining and passing arguments for prompt parameterization

Current behavior

There is no way to:

• Set a human-readable title for a prompt
• Define structured arguments for prompt customization

Why this matters

• title improves usability in UIs and tooling
• arguments are essential for building reusable and parameterized prompts
• Lack of support leads to incomplete spec compliance and limits interoperability

Suggested solution

• Extend the Prompt definition in the SDK to include:

  • title?: string
  • arguments?: array

• Ensure serialization/deserialization aligns with the MCP spec

• Optionally provide helper classes or typing for arguments