# Opus Prompting > Writing assistant that identifies artifact type (CLAUDE.md, skill, command, agent prompt) Use when this capability is needed. - Skill: `tomevault-io/opus-prompting` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/opus-prompting` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/opus-prompting/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/opus-prompting --- --- name: opus-prompting description: | Writing assistant that identifies artifact type (CLAUDE.md, skill, command, agent prompt) and surfaces relevant prompt patterns when invoked. Covers Claude's behavioral properties, over-specification prevention, and agentic workflow design. --- # Prompt Writing Assistant Claude follows natural language more literally than most models expect. The primary failure mode is **overtriggering and over-specification** — not under-compliance. Write less, trust more. If unsure whether these behavioral properties are current, check the system date and search for the latest Claude model documentation. ## Claude Behavioral Properties | Property | Implication | |----------|-------------| | Adaptive thinking (4 effort levels) | Let Claude calibrate reasoning depth; specify effort only at API level when needed | | 200K context window (1M in beta) | Long conversations maintain quality; 1M requires beta access | | Literal instruction following | Every instruction compounds — write guidelines, not rules | | High system prompt responsiveness | Natural language over directives; aggressive language causes overtriggering | | Overtriggering as primary failure mode | `MUST use [tool]` → tools fired when not needed; soften to `Use [tool] when...` | | Overeagerness / overengineering | Claude adds features, docs, error handling beyond what's asked; scope constraints help | | Prefilling deprecated | Assistant message prefilling is unsupported; use system prompt instructions or structured output | ## Applying These Patterns Read these artifact-type blocks to identify which patterns matter most for your current task. Pattern numbers reference `references/patterns.md`. ### CLAUDE.md Instructions **Key concern**: Over-specification compounds across every session. Each unnecessary rule burns token budget and can trigger the behaviors it's trying to prevent. - Pattern 1 (Aggressive language) — soften or remove `MUST`/`NEVER`/`CRITICAL`; they cause overtriggering in instructions that persist across sessions - Pattern 5 (Context/motivation) — one `because...` per constraint lets Claude generalize rather than memorize - Pattern 6 (Over-specification) — describe intent, not exhaustive rules; three similar lines beat a premature abstraction **Guidance**: Write guidelines a colleague would follow without needing to memorize them. If a rule triggers the behavior it's preventing (e.g., `NEVER be verbose` makes the prompt verbose), cut it. ### Skill Body (SKILL.md) **Key concern**: The `description` field in frontmatter is a token-budget signal — it controls when the skill loads into context. Lead with what the skill *does when invoked*, not what subject it covers. - Pattern 7 (Verbosity) — skill descriptions are ranking signals; every word must earn its place - Pattern 6 (Over-specification) — progressive disclosure: frontmatter triggers loading, body provides depth - Pattern 4 (Formatting) — match the skill's prose style to the output you want from the model **Guidance**: First sentence of `description` should be a verb phrase naming the activation behavior (e.g., "identifies X and surfaces Y" not "covers X, Y, and Z"). See also: `claude-skill-creator` skill. ### Slash Command Template **Key concern**: Command templates are read once per invocation. The model parses them linearly — structure (especially XML) matters more than in persistent context. - Pattern 8 (XML structure) — use semantic tags (``, ``, ``) to separate mutable from immutable sections - Pattern 4 (Formatting) — prompt format influences output format; structure the template like you want the output - Pattern 3 (Tool invocation) — conditional tool use (`Use [tool] when...`) prevents overtriggering in command workflows **Guidance**: Front-load the command's purpose and exit criteria. `$ARGUMENTS` substitution is a command-only feature — if this content is in a skill, arguments won't route. See also: `slash-command-creator` skill. ### Agent System Prompt **Key concern**: Agents are more literal than interactive sessions. Overtriggering is amplified because agents act autonomously on every instruction. - Pattern 1 (Aggressive language) — `MUST`/`ALWAYS` in agent prompts cause pathological tool loops - Pattern 3 (Tool invocation) — describe tools conditionally; agents will invoke every tool that sounds relevant - Pattern 6 (Over-specification) — agents handle novel situations better with principles than with exhaustive rules **Guidance**: Describe tool use conditionally (`Use X when Y`) not imperatively (`Always use X`). Test by asking: if this instruction fires incorrectly, what's the blast radius? ## Self-Check Before outputting, run these three tests: 1. **Golden rule**: Would a colleague with minimal context understand this without asking clarifying questions? 2. **Self-defeating instructions**: Does any instruction trigger the behavior it's preventing? (`MUST NOT be verbose` is itself verbose; `NEVER overthink` invites overthinking) 3. **How vs what**: Am I specifying *how* when the reader only needs *what*? (If yes, cut the how — Claude will find an appropriate implementation) ## References | File | Content | |------|---------| | `references/patterns.md` | 8 pattern categories with before/after examples and transformation rules | | `references/agentic-patterns.md` | Agent teams, delegation, tool design, state tracking, error handling | | `scripts/analyze-prompt.py` | CLI analyzer for deprecated patterns (configure via `scripts/config.json`) | --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/aeyeops) — claim your Tome and manage your conversions.