How to request documentation help in Tcl on the command line?

How can someone request help on a Tcl topic from the command line?

Does Tcl has a local documentation extractor/generator tool one can use to quickly get information about a Tcl command or a command out of a Tcl package/module like expect?

Something like pydoc in the Python world, or a specialized man?

I'm starting to use expect and would like to integrate such a tool to my editor so I could quickly look up Tcl reference information.

For example, on a given snippet of Tcl code like:

package require Expect

spawn bash

exp_send "ls -l\n"

set accum {}
expect {
    -regexp {..*} {
        set accum "${accum}$expect_out(0,string)" 
        exp_continue
    }
}

I'd like to be able to request information about package or exp_continue or any Tcl keyword or library command.

So far I did not find anything describing such a tool in the Tcl wiki.

At a tclsh prompt, you can try:

tclsh>  man lappend

On my system, (Linux w/ tcsh shell) this opened up the man page for lappend in a pager program (less, more, most). This is really for interactive use, I suppose, and I'm not sure how you would integrate this into another tool, like your editor.