estimate

Analyzes a task or GitHub issue and provides effort estimation broken into subtasks with T-shirt sizing, risk assessment, and dependency mapping. Use for sprint planning or before committing to deadli

SKILL.md

GitHub

Effort Estimation

Context

!gh issue view $1 2>/dev/null || echo "Provide a task description or issue number"


Estimation Process

Step 1: Scope Analysis

  1. Read the task/issue description carefully
  2. Search the codebase to understand current state
  3. Identify all files, modules, and systems that would be affected
  4. Check for existing implementations that can be reused

Step 2: Task Breakdown

Decompose the work into subtasks. For each subtask:

Subtask Files Affected Size Confidence
... ... S/M/L/XL High/Med/Low

Size Guide:

  • S (Small): < 2 hours — single file change, straightforward logic
  • M (Medium): 2-6 hours — multiple files, some complexity, needs tests
  • L (Large): 1-2 days — cross-module changes, new patterns, significant testing
  • XL (Extra Large): 3-5 days — architectural changes, new infrastructure, coordination needed

Step 3: Risk Assessment

Identify risks that could expand the estimate:

Risk Probability Impact Mitigation
... High/Med/Low +S/+M/+L ...

Common risks:

  • Unclear requirements → ask clarifying questions first
  • Legacy code with no tests → add time for writing tests
  • External dependencies → add time for integration
  • Database migrations → add time for rollback planning
  • API changes → add time for consumer coordination

Step 4: Dependencies

List any blockers or prerequisites:

  • Other issues that must be completed first
  • External services or APIs that must be available
  • Team members who need to be consulted
  • Infrastructure or access requirements

Step 5: Total Estimate

Scenario Estimate Assumption
Best case ... Everything goes smoothly, no surprises
Likely case ... Normal amount of debugging and iteration
Worst case ... Major risks materialize

Rules

  • Be honest — over-optimistic estimates hurt more than conservative ones
  • Include testing and review time in estimates
  • Flag any assumptions you're making
  • If the task is too vague to estimate, say so and list the questions that need answers