Before You File a Proposal Please Confirm You Have Done The Following...

• I have searched for related issues and found none that match my proposal.
• I have searched the current rule list and found no rules that match my proposal.
• I have read the FAQ and my problem is not listed.

My proposal is suitable for this project

• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Link to the rule's documentation

https://typescript-eslint.io/rules/no-unnecessary-type-parameters/

Description

Add suggestions with the intended fix.

Fail

function toUnknown<T>(x: T): unknown {
    return x;
}

function withExtends<T extends number | string>(x: T): unknown {
    return Math.random();
}

Pass

// replace unconstrained input generic with unknown
function toUnknown(x: unknown): unknown {
   return x;
}

// replace constrained input generic with its constraint type
function withExtends(x: number | string): unknown {
    return Math.random();
}

Additional Info

There are probably more cases where we could make suggestions, too. These are just the first things that came to mind. I think that adding these suggestions would have high value to help the user understood why the rule is reporting, since this rule is quite subtle