SKILLEMALL.ai

BC change-detection

Multi-temporal change detection for satellite imagery using NDVI difference, description: 'Multi-temporal change detection for satellite imagery using NDVI difference, image differencing, and Change Vector Analysis (CVA). Detects vegetation, urban, and water changes.

ClawHub Agent Skills author: ruiduobao v1.0.0 MIT-0 6 files body ≈ 2 834 tokens Open the sourceclawhub.ai analyzed 30 h ago

Multi-temporal change detection for satellite imagery using NDVI difference, description: 'Multi-temporal change detection for satellite imagery using NDVI…

As a process C 55/100 · Has gaps — weak spots: when it triggers, inputs and preconditions, consistency

AnalyzerGitHubData and analyticsInfrastructureResearchtype and topics are labelled automatically from the skill text
JSON
Technical rating
B
88/100
safety, quality, tests
Safety 60%
100
Quality 40%
69
Run on models
none yet
Process rating
C
55/100
Has gaps
Inputs and preconditions w 11
0
Progress reporting w 2
0
When it triggers w 12
20
the three weakest of ten parameters · all ten

How to improve

  1. Say in the description WHEN to use the skill ("use when…", example requests): that is the agent's main cue.
For the model run — optional
  • 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 · 0

✓ No critical or high findings

Files scanned: 6. Evidence is masked. Grey chips explain why severity was lowered.

Against the Agent Skills spec

  • warning frontmatter-yaml SKILL.md: the frontmatter is not valid YAML (YAML parse error: Unexpected scalar at node end at line 2, column 106: …y using NDVI difference, description: 'Multi-temporal change detection for sat… ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ); fields were read line by line. The usual cause is a colon inside an unquoted value
  • warning description-no-when description does not say WHEN to use the skill (no "use when")

Process rating: all ten parameters 55/100

  • 0Inputs and preconditions. Does not say what the process needs to start
  • 0Progress reporting. Says nothing while it works
  • 20When it triggers. No condition that starts the skill
  • 40Consistency. Frontmatter name (change-detection) differs from the folder (geoskill-change-detection)
  • 50Failures and branches. 0 branches, has a failure section
  • 60Tools and files. Uses tools (python) that frontmatter does not declare
  • 60Result and completion. Output format stated, no completion criterion
  • 100Steps. 73 steps
  • 100Execution cost. Instruction body is 2834 tokens
  • 100Running it twice. No mutating operations
  • low 38 top-level sections: this looks like several domains in one skill

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)
  • +2Single-language instructions
  • +3Description length 269: enough signal without eating the budget
  • +4Structure: 49 headings
  • +3Step-by-step instructions: 73 items
  • +3Output format is stated explicitly
  • +4Has examples (19 code blocks)
  • +3All 1 scripts are documented
  • +1License stated

Quality base 70; lint remarks subtract, signals add up to 100. Result: 69.

External checks

ClawHub: suspicious
The skill mostly matches satellite change detection, but it under-discloses a networked image-fetch feature while claiming all processing is local.
LLM: suspicious (high) · 1 Aug 2026