v1.5.0 — Performance Snapshot Tool

What's new

A new MCP tool — capture_performance_snapshot — that lets your AI assistant get a quick, structured read on Unity performance without you having to open the Profiler.

Why it's useful

Before: "the scene feels laggy" was a subjective handoff. You'd open the Profiler, eyeball the graph, screenshot it, paste numbers into chat.

Now: one tool call returns hard data — "max frame time 106ms vs 16.6ms target, 174 samples over 3s". Your AI agent can act on facts instead of guesses, and even close the loop: change code → re-snapshot → compare.

What it captures

• In Play Mode: frame timing (avg/min/max ms + fps) sampled every frame after a configurable warmup, plus memory (Profiler.GetTotalReservedMemoryLong, Mono heap/used).
• In Edit Mode: memory only, with an honest warning. The tool refuses to fake frame timing from editor repaints — those numbers would be meaningless.
• Warnings: fires when any frame exceeds the targetFpsThreshold budget, or when memory counters come back empty.

Parameters

Param	Default	Notes
durationSeconds	5	Post-warmup sampling window
warmupSeconds	1	Frames during warmup are discarded
targetFpsThreshold	60	Used for the over-budget warning
includeMemory	true	Skip if you only want frame stats

Duration is auto-clamped to fit inside RequestTimeoutSeconds - 5s and hard-capped at 20s, so MCP calls never hang.

Example prompts

• "Capture a 5 second performance snapshot while the game is running."
• "Take a memory snapshot of the editor right now."
• "Sample frames for 10 seconds at 30fps target and tell me if we miss budget."

Notes for upgraders

• No breaking changes. New tool only.
• Locale-safe text output (1.0s, 56.2 fps) regardless of system locale.
• 12 new tests (7 NUnit + 5 Jest), all green; full Node suite at 190/190.

Out of scope (planned for later)

• start_performance_capture / stop_performance_capture for sessions longer than 20s
• ProfilerRecorder-based counters (render thread, GC alloc, physics)
• Memory Profiler .snap integration