The /usr/bin/otool file is a "developer shim" the real command line tool is located within a particular Xcode package.
Do you have Xcode installed?
(I'm not sure if you can install the command line tools without installing Xcode.)
You may have multiple versions of Xcode installed, you then use xcode-select to point to the actual executables.
Read the man page for xcode-select
When I run 'otool' with no arguments I get the following usage statement
Usage: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/ usr/bin/otool [-arch arch_type] [-fahlLDtdorSTMRIHGvVcXmqQjC] [-mcpu=arg] [--version] <object file> ...
-f print the fat headers
-a print the archive header
-h print the mach header
-l print the load commands
-L print shared libraries used
-D print shared library id name
-t print the text section (disassemble with -v)
-p <routine name> start dissassemble from routine name
-s <segname> <sectname> print contents of section
-d print the data section
-o print the Objective-C segment
-r print the relocation entries
-S print the table of contents of a library
-T print the table of contents of a dynamic shared library
-M print the module table of a dynamic shared library
-R print the reference table of a dynamic shared library
-I print the indirect symbol table
-H print the two-level hints table
-G print the data in code table
-v print verbosely (symbolically) when possible
-V print disassembled operands symbolically
-c print argument strings of a core file
-X print no leading addresses or headers
-m don't use archive(member) syntax
-B force Thumb disassembly (ARM objects only)
-q use llvm's disassembler (the default)
-Q use otool(1)'s disassembler
-mcpu=arg use `arg' as the cpu for disassembly
-j print opcode bytes
-C print linker optimization hints
--version print the version of /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/ usr/bin/otool
