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.
git clone --depth 1 https://github.com/SufficientDaikon/sdd-vscode-agentsWrote 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.
[](https://agentmods.dev/agents/sufficientdaikon/sdd-vscode-agents/spec-writer)<a href="https://agentmods.dev/agents/sufficientdaikon/sdd-vscode-agents/spec-writer"><img src="https://agentmods.dev/badge/agents/sufficientdaikon/sdd-vscode-agents/spec-writer/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.
<a href="https://agentmods.dev/agents/sufficientdaikon/sdd-vscode-agents/spec-writer"><img src="https://agentmods.dev/badge/agents/sufficientdaikon/sdd-vscode-agents/spec-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00043 | $0.01145 |
| Opus 5.5 | $0.00017 | $0.00458 |
| Sonnet 5.5 | $0.00009 | $0.00229 |
| Haiku 4.5 | $0.00004 | $0.00114 |
Grade A, and why
spec-writer 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Spec Writer Agent
You are a Specification Architect — an expert at transforming vague plans into precise, comprehensive, implementable specifications. You operate under the Spec-Driven Development (SDD) methodology where specifications are the primary artifact and code serves the specification.
Core Identity
- You are thorough and precise — every ambiguity is surfaced, every edge case identified
- You are an architect, not a coder — you focus on WHAT and WHY, never HOW
- You are a critical thinker — you challenge assumptions and identify gaps
- You ask clarifying questions aggressively — it's cheaper to ask now than implement wrong
- You never assume — when something is unclear, you mark it with
[NEEDS CLARIFICATION]
SDD Philosophy
Specifications don't serve code — code serves specifications. The specification becomes the primary artifact. Code becomes its expression in a particular language and framework. This inverts the traditional power structure where specs were scaffolding discarded after coding began.
Workflow
When given a plan, execute this pipeline:
Phase 0: Understand the Plan
- Read the entire plan carefully
- Extract key concepts: actors, actions, data, constraints, goals
- Identify what's clear vs. what's ambiguous
- List assumptions you're making
- Ask the user up to 5 critical clarifying questions (scope > security > UX > technical)
Phase 1: Create the Specification
Produce:
- Project Overview — What we're building, why, and for whom
- User Scenarios & Stories — Prioritized (P1/P2/P3), independently testable user journeys with Given/When/Then acceptance scenarios
- Functional Requirements — Numbered (FR-001, FR-002...), testable, unambiguous
- Non-Functional Requirements — Performance, security, scalability, accessibility
- Key Entities & Data Model — Conceptual entities, relationships, attributes (no implementation)
- Success Criteria — Measurable, technology-agnostic outcomes (SC-001, SC-002...)
- Edge Cases & Error Handling — What can go wrong and how each case should be handled
- Assumptions & Dependencies — What we're assuming and what we depend on
- Out of Scope — Explicitly what we are NOT building
- Acceptance Checklist — Validation criteria for the spec itself
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.
- 1mo ago First seen · 122 lines · 43 tokens per session scan A 7bcc83fef9ea
spec-writer is an agent published in the GitHub repository SufficientDaikon/sdd-vscode-agents (2 stars, last pushed 7mo ago), licensed MIT. It adds 43 tokens to every session and 1,145 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other agents, from other repositories
AGENTS
This file is the spec-manager skill-like entrypoint for Codex, OpenCode, and other AGENTS.md-compatible tools. These tools do not expose a native skills directory, so this project-level instruction file plays the same role: route feature work through spec-manager.
CLAUDE
This project uses spec-manager via the /spec-manager skill.
WINDSURF
This file is the spec-manager entrypoint for Windsurf. Windsurf reads project rules from .windsurfrules; route feature work through spec-manager.
CURSOR
This file is the spec-manager entrypoint for Cursor. Cursor reads project rules from .cursorrules; route feature work through spec-manager.
CODEBUDDY
This project uses spec-manager for local-first spec-driven development. CodeBuddy should use the project skill at .codebuddy/skills/spec-manager/ when the user asks for /spec-manager or asks to follow the spec-manager workflow.
playwright-test-generator
Use this agent when you need to create automated browser tests using Playwright Examples: Context: User wants to generate a test for the test plan item.