Add support for specifying null values for tool fields

[gregsaab]

This adds the ability to specify a null value for nullable fields by conditionally rendering a null checkbox when a field has a null type in the array. If the checkbox is selected, the input will be disabled.

I chose checkboxes over supporting a value of "null" to make behavior explicit, obvious, and not to affect cases where you actually want to send "null" as a value.

Example:

Note

When reviewing, hide whitespace changes

Motivation and Context

At present, there is no way to specify a null value for a field.

How Has This Been Tested?

• Tested against a local MCP server with non-nullable and nullable fields (various types), and verified that correct values received by mcp server
• Added unit & ui test specs

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

[cliffhall]

Hi @gregsaab!

Interestingly, there is another PR @olaservo is working on where the challenge is to send null for a field whose default is null in the tool's inputSchema.

[gregsaab]

Hi @gregsaab!

Interestingly, there is another PR @olaservo is working on where the challenge is to send null for a field whose default is null in the tool's inputSchema.

Hey @cliffhall yeah, I saw that soon after I submitted this. Thought it would be worth having an alternative approach in the mix!

[cliffhall]

@gregsaab can you merge main on your branch and resolve conflicts? There have been some changes to the ToolsTab.tsx.

[gregsaab]

merge

@cliffhall done 3adddfb