Improve JSON Schema explanation and add reference link in "Tool definition structure" section

Description

In the official MCP documentation, under the section "Tool definition structure", the field inputSchema is described as:

inputSchema: {
  type: "object",
  properties: { ... } // Tool-specific parameters
}

However, the current description lacks clarity that this is expected to conform to the JSON Schema specification. This may lead to confusion for developers unfamiliar with the protocol.

Suggestion

• Clarify that the inputSchema field should follow the JSON Schema specification.
• Add a reference link to https://json-schema.org/ directly in the documentation to help developers understand the structure and capabilities of JSON Schema.

Example update (suggested inline comment)

inputSchema: {
  type: "object",
  properties: { ... } // Tool-specific parameters (must conform to JSON Schema: https://json-schema.org/)
}

This improvement would make the documentation more developer-friendly and self-explanatory.