fastcontext-agent-tools

Use Microsoft FastContext as the default read-only code exploration subagent before answering, editing, reviewing, or debugging code you are not already certain about. Trigger when a task requires reading more than one file, tracing logic across modules, locating files/symbols/call paths/tests, mapping dependencies, assessing change impact, or finding where behavior is implemented. Use it instead of manual grep/glob/read chains when broad exploration would consume main-agent context. Do not use for already-read exact files, a single obvious grep in one known file, pure generation tasks with no exploration need, tiny single-file tasks, or non-code questions.