Fetches full schema definitions for deferred tools so they can be called.

Deferred tools appear by name in system-reminder messages. Until fetched, only the name is known — there is no parameter schema, so the tool cannot be invoked. This tool takes a query, matches it against the deferred tool list, and returns the matched tools' complete schema definitions.

Query forms:
- "select:Read,Edit,Grep" — fetch these exact tools by name
- "notebook jupyter" — keyword search, up to max_results best matches
- "+slack send" — require "slack" in the name, rank by remaining terms

Result format: each matched tool appears with its full name, description, and JSON schema for parameters.