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 skills add uselessspace/freedeepagents-activity-builder --skill activity-diagnosticiangit clone --depth 1 https://github.com/uselessspace/freedeepagents-activity-builderWrote 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/uselessspace/freedeepagents-activity-builder/activity-diagnostician)<a href="https://agentmods.dev/skills/uselessspace/freedeepagents-activity-builder/activity-diagnostician"><img src="https://agentmods.dev/badge/skills/uselessspace/freedeepagents-activity-builder/activity-diagnostician/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/skills/uselessspace/freedeepagents-activity-builder/activity-diagnostician"><img src="https://agentmods.dev/badge/skills/uselessspace/freedeepagents-activity-builder/activity-diagnostician.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 | $0.00169 | $0.01138 |
| Opus 5 | $0.00084 | $0.00569 |
| Sonnet 5 | $0.00034 | $0.00228 |
| Haiku 4.5 | $0.00017 | $0.00114 |
Grade A, and why
activity-diagnostician 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 10d 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 — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Activity Diagnostician
<builder-root> 指从本 SKILL.md 所在目录向上两级、包含根 SKILL.md 与
tools/ 的目录；不要假定它位于目标项目的 packages/ 下。
何时用：活动跑出问题要 debug 时——给
turn_id/ 错误日志 / 症状描述任一即可。/activity-smoke判定失败后通常转到这里。
Own the "turn failed — what went wrong" path. Each error class in references/error-classes.md maps a trace signature to a root cause, a fix location, and the validation step that confirms the fix.
Input forms
Three accepted; pick the one with the most signal:
turn_id(preferred) — e.g.4daad15531a247c9938b355f2eb1d25e. Locateruntime/instances/<activity_type_id>/<instance_id>/turns/<turn_id>/; theinput.jsonshows what the user sent andtrace.jsonlshows what the runtime / LLM / tools did. Walk to workflows/from-turn-id.md.- Error log / stack trace pasted by user — the user copied a message like
BadRequestError(...)orOutputValidationError: .... Walk to workflows/from-error-log.md. - Symptom description ("卡片重复 / agent 没反应 / 渲染丢字段") — read
references/error-classes.md row by row;
each class lists a "user-visible symptom" hint. Match symptom → class →
request a
turn_idto confirm.
When the turn ran on a reachable shared dev runtime but no local trace is
available, route through /activity-dev-cli: run doctor, then
fda-dev --folder <activity-folder> logs, and inspect the downloaded
fda-logs/ snapshot. logs is read-only on the server but writes a local
diagnostic snapshot. Do not guess a trace from the visible UI alone; see
../../references/dev-agent-cli.md.
Output
A short diagnosis with three sections:
## Diagnosis
- Error class: <class id from error-classes.md>
- Root cause: <one sentence>
- Trace evidence: <quoted line(s) from trace.jsonl>
## Fix
- Edit `<exact file path>`: <what to change>
- Authoritative policy: `<path-to-skill-file> §<section>`
## Validation
- Run `<command>` and look for `<expected output>`
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 97 lines · 169 tokens per session scan A bdbe68ce0752
activity-diagnostician is a skill published in the GitHub repository uselessspace/freedeepagents-activity-builder (2 stars, last pushed 22d ago), licensed MIT. It adds 169 tokens to every session and 1,138 once invoked, about $0.0008 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 2026-08-31.
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