BC trycloudflare-proxy-verify
Expose a local file, local folder, screenshot, or local HTTP service through a temporary trycloudflare.com tunnel and verify the public URL before sharing it. Use when a user asks for a downloadable URL to local resources, local web pages, local screenshots, local generated artifacts, or any machine-local content that should be shared externally. Always verify the final public URL yourself before returning it.
As a process C 61/100 · Has gaps — weak spots: result and completion, inputs and preconditions, running it twice
What is at stake
Medium-severity findings: the skill is probably honest, but read what alarmed the scanner.
Below is the worst case for this category. The finding here is medium: the guard saw a sign, not a proof.
The instructions or scripts send data out: environment variables, keys, file contents, chat history. You may never notice, because the agent performs the upload as "part of the task".
If the upload is not needed for the task, remove it: catalogs flag such skills and delist them. If it is needed, name the destination explicitly, say what leaves the machine, and give the user a switch.
How to improve
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 3
✓ No critical or high findings
Medium and low: 3
-
medium Exfiltration
exfil-webhook-urlreferences/verification-checklist.md:7Webhook / callback URL commonly used for exfiltration (verify the destination) (quoted — discussed, not commanded)2. `cloudflared` logs show a generated `https://*.trycloudflare.com` URL.
quoted -
medium Exfiltration
exfil-webhook-urlSKILL.md:32Webhook / callback URL commonly used for exfiltration (verify the destination) (quoted — discussed, not commanded)4. Poll logs until a `https://*.trycloudflare.com` URL appears and the tunnel registers successfully.
quoted -
low Exfiltration
exfil-webhook-urlreferences/verification-checklist.md:11Webhook / callback URL commonly used for exfiltration (verify the destination) (placeholder value)- Example: `curl -I https://example.trycloudflare.com/file.zip`
placeholder
Files scanned: 4. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
✓ No remarks against the Agent Skills spec
Process rating: all ten parameters 61/100
- 0Result and completion. Does not say what the result is
- 0Inputs and preconditions. Does not say what the process needs to start
- 30Running it twice. 1 mutating operations with no state check
- 60Tools and files. Uses tools (web, python) that frontmatter does not declare
- 70When it triggers. States when to use, but not when not to
- 100Steps. 22 steps
- 100Failures and branches. 2 branches, has a failure section
- 100Consistency. Name and required fields are in place
- 100Execution cost. Instruction body is 441 tokens
- 100Progress reporting. Reports progress
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
- +5Description has no quoted example phrases that should trigger the skill
- +4Description does not say when NOT to use the skill (false activations)
- +3Output format is not stated: the model decides each time
- -2localhost URLs: will not work for another user
- +1No license
- +2Single-language instructions
- +3Description length 413: enough signal without eating the budget
- +4Structure: 9 headings
- +3Step-by-step instructions: 22 items
- +4Has examples (0 code blocks)
- +4Reference files are cited in the instructions (1 of 1)
- +3All 1 scripts are documented
Quality base 70; lint remarks subtract, signals add up to 100. Result: 89.