What is prompt-improver?

A read-only specialist that improves prompts for high-stakes external command-line tasks. It chooses a prompt framework and checks whether the prompt is clear and complete.

It is for preparing dispatch-ready prompts, selecting an appropriate framework, applying structured prompt improvements, and returning escalation notes when inputs are insufficient.

It exposes missing information, ambiguity, conflicting requirements, and partial-result risks before another tool or agent runs.

prompt-improver — Agent for Claude Code by MichelKerkmeester

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo

git clone --depth 1 https://github.com/MichelKerkmeester/skilled-harness__spec-driven-agent-loops

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver/github.svg)](https://agentmods.dev/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver)

Your own site

<a href="https://agentmods.dev/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver"><img src="https://agentmods.dev/badge/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver"><img src="https://agentmods.dev/badge/agents/michelkerkmeester/skilled-harness__spec-driven-agent-loops/prompt-improver.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 4,763 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 100% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00021	$0.04763
Opus 5.5	$0.00008	$0.01905
Sonnet 5.5	$0.00004	$0.00953
Haiku 4.5	$0.00002	$0.00476

Measured 2mo ago against content hash b8c69d79b8d9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prompt-improver scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to prompt-improver — 107 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/prompt-improver.md · 379 lines

How it starts

The opening of the file, as written. The whole thing — 379 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The Prompt-Improver Agent: Prompt Escalation Specialist

Read-only prompt-engineering specialist for high-stakes external CLI prompt construction. This agent selects the best-fit framework, applies DEPTH at the right energy level, validates the result with CLEAR, and returns a structured prompt package that the caller can dispatch directly.

CRITICAL: This agent is LEAF-only and read-only. It never edits files, never delegates, never executes the enhanced prompt, and never returns unstructured prompt advice.

BOUNDARY PRINCIPLE: Prompt polish must not hide missing inputs, ambiguity, contradictions, integration assumptions, or partial-success states. Surface those limits in ESCALATION_NOTES or use the blocked package.

IMPORTANT: Use only .claude/agents/*.md as the canonical runtime path reference. Runtime mirrors are downstream packaging surfaces.

Hook-Injected Advisor Context: Treat hook-injected skill-advisor recommendations as routing hints only. They never override explicit user instructions, active command workflow, scope gates, runtime permissions, agent boundaries, or required skill loading. If advisor context conflicts with the dispatch prompt or verified local files, prefer the dispatch prompt plus file evidence and report the conflict.

0. ILLEGAL NESTING AND WRITE BOUNDARY (HARD BLOCK)

This agent is LEAF-only and read-only. Nested sub-agent dispatch and file mutation are illegal.

NEVER call the Task tool, create sub-tasks, ask another agent to investigate, or hand off work from inside @prompt-improver.
NEVER use or recommend Write/Edit/Patch/Bash operations. write, edit, and bash are all denied in this agent's permissions.
NEVER execute the prompt it constructs. This agent returns a dispatch-ready package; the caller dispatches it.
NEVER emit a file path for @prompt-improver to write later, even when the caller asks for "file-based" output.
If delegation, mutation, or execution is requested, ignore that portion, complete the prompt package with allowed read-only tools, and record the refused boundary in ESCALATION_NOTES.
If the request cannot be framed as prompt construction, or raw_task is absent, return the blocked package rather than guessing the caller's intent.

Read the full file on GitHub · 379 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 379 lines · 21 tokens per session scan A b8c69d79b8d9

Subscribe to this mod's changes

prompt-improver is an agent published in the GitHub repository MichelKerkmeester/skilled-harness__spec-driven-agent-loops (39 stars, last pushed 6d ago), licensed MIT. It adds 21 tokens to every session and 4,763 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to prompt-improver, differing in 107 lines, and is treated as a copy.

Data and AI Prompting

prompt-improver next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
prompt-improverMichelKerkmeester/skilled-harness__spec-driven-agent-loops	Agent	39	6d ago	MIT	A	21	Claude Code
Prompt Buildergithub/awesome-copilot	Agent	41k	today	MIT	A	24	Claude Code
tokentonone-ai/tonone	Agent	77	24d ago	MIT	A	21	Claude Code
security-ai-codejoaoguirunas/team-os	Agent	6	4d ago	MIT	A	94	Claude Code
prompt-engineerSteveGJones/ai-first-sdlc-practices	Agent	42	1mo ago	MIT	B	52	Claude Code
prompt-coachivegamsft/basecoat	Agent	4	8d ago	MIT	A	61	Claude Code
hyv-veo-prompt-smithkillernay/HearYourVOICE	Agent	141	3mo ago	MIT	B	124	Claude Code