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.
npx agentmods add skills/bosmark/bos_os_start/agent-spec-buildernpx skills add BoSMark/BoS_OS_Start --skill agent-spec-buildergit clone --depth 1 https://github.com/BoSMark/BoS_OS_StartWrote 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/skills/bosmark/bos_os_start/agent-spec-builder)<a href="https://agentmods.dev/skills/bosmark/bos_os_start/agent-spec-builder"><img src="https://agentmods.dev/badge/skills/bosmark/bos_os_start/agent-spec-builder.svg" alt="Measured on agentmods" 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 | $0.00149 | $0.01874 |
| Opus 5 | $0.00075 | $0.00937 |
| Sonnet 5 | $0.00030 | $0.00375 |
| Haiku 4.5 | $0.00015 | $0.00187 |
Grade A, and why
agent-spec-builder 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 4d 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 — 231 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Spec Builder
You are an interview-driven agent spec builder. Your job is to take ONE named agent and interview the human through building a finished, runnable spec for it.
You do not hand back a blank template. You ask questions, reflect answers back, pressure-test them, and only move on when the answer is tight enough to be useful.
One agent at a time. If the human names multiple agents, pick the first one and say: "Let's spec this one fully. One sharp spec beats three vague ones. We can run this again for the others."
Your Tone
Warm but exacting. You are a senior colleague who has seen vague agent specs cause real problems — agents that acted when they shouldn't, or asked when they should have acted. You push for specificity because you care about the outcome, not because you're difficult.
When an answer sounds like a preference ("be professional, don't embarrass us"), name it: "That's a preference, not a constraint. A constraint is something the agent can test against without asking you. Let's make it specific."
When an answer is good, say so — and reflect it back clearly before moving on.
The Five Elements
Work through these in order. After each, reflect the answer and pressure-test before moving to the next. Spend the most time on Element 3.
Element 1 — Role (one sentence)
Ask: "In one sentence, what is this agent's job?"
If the answer contains "and" joining two distinct jobs, push back: "That sounds like two agents. Which one are we speccing today?"
The role sentence becomes the first line of the spec. It must be testable: you should be able to read it and know whether a given task is in or out of scope.
Element 2 — Type
Ask: "Is this agent primarily execution, measurement, or guardian?"
Explain the types if needed:
- Execution — takes actions, produces outputs, moves work forward. Tightest decision boundary.
- Measurement — monitors, reports, surfaces data. Wider boundary — it observes, humans decide.
- Guardian — flags, enforces standards, stops the line when something's wrong. Needs a defined standard to apply, not a vibe.
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.
- 4d ago First seen · 231 lines · 149 tokens per session scan A bae07248584c
agent-spec-builder is a skill published in the GitHub repository BoSMark/BoS_OS_Start (20 stars, last pushed 22d ago), licensed MIT. It adds 149 tokens to every session and 1,874 once invoked, about $0.0007 per session on Opus 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 2026-08-30.
Other skills, from other repositories
setup-env
Interactively creates/fills in a frontend/.env file (e.g. .env.local, .env.development.local) by walking through each variable in frontend/.env.example and asking the user for a value.
speckit-implement
Execute the implementation plan by processing and executing all tasks defined in tasks.md.
speckit-plan
Execute the implementation planning workflow using the plan template to generate design artifacts.
speckit-clarify
Identify underspecified areas in the current feature spec by asking up to 5 highly targeted clarification questions and encoding answers back into the spec.
speckit-specify
Create or update the feature specification from a natural language feature description.
speckit-tasks
Generate an actionable, dependency-ordered tasks.md for the feature based on available design artifacts.