BD image-downloader
当用户需要按关键词批量下载图片、从 Bing 或多个图片来源收集候选、保存图片到本地目录、避免重复下载，或希望复用当前仓库里的现成图片下载流程时使用。遇到类似“帮我按关键词下载 10 张图片”“批量抓取 Bing 图片并保存到本地”“从多个来源收集图片候选再下载”“需要下载摘要和保存目录”这类请求时，应主动使用这个 skill。
As a process D 43/100 · Unfinished process — weak spots: result and completion, when it triggers, inputs and preconditions
What is at stake
The skill contains fragments that, in the wrong hands, cost money or data. Below: what the installer risks and what the author should do.
The skill contains commands that delete files, rewrite disks or execute code fetched from the network. The agent may run them without asking if it believes the instructions require it.
Replace destructive commands with safe equivalents that ask for confirmation, scope them to one folder, and stop piping curl into a shell: pin a version and a checksum.
How to improve
- Address the high-severity findings: each costs 18 safety points. If one is a false positive, add the rule id to guard.allow in spec.yaml.
- Say in the description WHEN to use the skill ("use when…", example requests): that is the agent's main cue.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 3
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high Dangerous commands
cmd-persistenceREADME.md:297Persistence mechanism (cron / launchd / scheduled task / autorun registry)crontab -l | { cat; echo '0 9 * * * TZ=Asia/Shanghai /path/to/scripts/image_download_daily.sh'; } | crontab -
Medium and low: 2
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low Dangerous commands
cmd-cron-mentionREADME.md:291Mentions editing / listing crontabcrontab -l
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low Dangerous commands
cmd-cron-mentionREADME.md:297Mentions editing / listing crontabcrontab -l | { cat; echo '0 9 * * * TZ=Asia/Shanghai /path/to/scripts/image_download_daily.sh'; } | crontab -
Files scanned: 17. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
description-no-whendescription does not say WHEN to use the skill (no "use when")
Process rating: all ten parameters 43/100
- 0Result and completion. Does not say what the result is
- 0Inputs and preconditions. Does not say what the process needs to start
- 0Failures and branches. Linear process with no failure handling
- 0Progress reporting. Says nothing while it works
- 20When it triggers. No condition that starts the skill
- 30Running it twice. 1 mutating operations with no state check
- 60Tools and files. Uses tools (bash, python) that frontmatter does not declare
- 100Steps. 59 steps
- 100Consistency. Name and required fields are in place
- 100Execution cost. Instruction body is 808 tokens
- low 11 top-level sections: this looks like several domains in one skill
- medium 4 test cases, all positive: not one "should refuse" or "should ask first"
- low No test case covers injection arriving through data
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +4Description does not say when NOT to use the skill (false activations)
- +3Output format is not stated: the model decides each time
- +1No license
- +2Single-language instructions
- +5Description quotes 4 example trigger phrases
- +3Description length 165: enough signal without eating the budget
- +4Structure: 22 headings
- +3Step-by-step instructions: 59 items
- +4Has examples (8 code blocks)
- +3All 1 scripts are documented
Quality base 70; lint remarks subtract, signals add up to 100. Result: 80.