Beef up MCP tool docstrings with workflow guidance

The existing docstrings are terse one-liners that work for humans glancing
at the code but leave LLM clients guessing about how the tools chain
together. Mirror the more verbose style we ship in the external
galaxy-mcp project: each tool now leads with what it's for, then lists
args, return shape, and (where it helps) a RECOMMENDED WORKFLOW or
NEXT STEPS section pointing at the next likely call. No behavior
changes, just documentation -- the same wrappers around
AgentOperationsManager.

Author: dannon