Require a trial period with pre-defined success metrics and a scheduled exit date before any new tool enters your stack permanently

Why This Is a Rule

Tools enter stacks easily and leave with great difficulty. Installing a new app takes 2 minutes; removing it after 6 months of accumulated data, workflow integration, and habit formation takes weeks. This asymmetry means every tool added to your stack has a high probability of permanent residency regardless of whether it proves valuable. The trial period with exit date converts easy-in/hard-out into a deliberate admission process.

Pre-defined success metrics prevent the common justification loop: "I should keep using this because I've been using it" (sunk cost). Instead, the metrics decided before the trial — "This tool earns its place if I use it 3+ times per week and it saves 15+ minutes per use" — provide an objective evaluation independent of habit or investment. The scheduled exit date creates a forcing function: on day 30, either the metrics are met (tool stays) or they're not (tool goes). No indefinite "I'll evaluate eventually."

This is Pick a tool with 5 minimum requirements, select the first that meets them, commit for 90 days — satisfice, don't maximize's 90-day commitment applied to the trial phase: the trial period gives the tool a fair chance (you use it genuinely, not halfheartedly) while protecting your stack from permanent additions that don't earn their place.

When This Fires

• When considering adding any new tool to your workflow
• When your tool stack has grown without deliberate curation
• When tools seem to accumulate without any being removed
• Complements Pick a tool with 5 minimum requirements, select the first that meets them, commit for 90 days — satisfice, don't maximize (90-day commitment) with the admission protocol that precedes commitment

Common Failure Mode

Permanent trial: installing a tool "to try it out" with no exit date or success metrics. Six months later, it's part of your stack by default — not because it proved valuable, but because removing it would require effort and you've gotten used to its presence. The tool is consuming maintenance overhead without having demonstrated value.

The Protocol

(1) Before installing any new tool, write down: Success metrics (what must be true for this tool to earn permanent status — usage frequency, time saved, specific capabilities used) and Exit date (when the trial ends — typically 2-4 weeks for simple tools, 4-8 weeks for complex ones). (2) During the trial, use the tool genuinely as part of your workflow. Don't hold back because "it's just a trial." (3) On the exit date, evaluate against the pre-defined metrics. Metrics met → tool is admitted permanently. Integrate fully and invest in mastery (Invest in mastery proportional to frequency × impact — months of practice for daily consequential tools, basic competence for infrequent ones). Metrics not met → tool is removed. Uninstall, export any data, and move on. No extensions, no "maybe one more week." (4) The trial period ends with an active decision (keep or remove), never with passive continuation. (5) For tools that barely miss metrics: either the metrics were wrong (revise for a second trial) or the tool isn't valuable enough (remove without guilt).