Koog 1.0 idioms, gotchas, and scaffolding skills for Kotlin agents on the JVM
87
88%
Does it follow best practices?
Impact
87%
1.85xAverage score across 45 eval scenarios
Advisory
Suggest reviewing before use
{
"context": "Tests whether the agent reaches for the event handler feature for human-readable per-step output — the right tool for development/demo surface — rather than reaching for OpenTelemetry (production signal, overkill here) or hand-rolling println scaffolding inside tool bodies.",
"type": "weighted_checklist",
"checklist": [
{
"name": "Installs the event-handler feature",
"description": "Calls handleEvents { ... } inside the AIAgent(...) trailing lambda. Does NOT install OpenTelemetry (overkill for stdout demo output and adds collector setup) and does NOT add println calls inside each tool body",
"max_score": 30
},
{
"name": "Adds the agents-features-event-handler dependency",
"description": "Adds ai.koog:agents-features-event-handler to build.gradle.kts at 1.0.0 or later. The umbrella does not include the event handler",
"max_score": 20
},
{
"name": "Subscribes to onToolCallStarting",
"description": "Registers an onToolCallStarting handler that prints tool name and arguments. The start-side callback is essential for the live demo trace",
"max_score": 20
},
{
"name": "Subscribes to onToolCallFinished",
"description": "Registers an onToolCallFinished handler that prints the tool result (or at minimum a completion marker). The task requires surfacing when each tool completes — both start and finish callbacks are needed",
"max_score": 15
},
{
"name": "Uses distinct visual markers for start vs end",
"description": "Uses visually distinct prefixes between start and end output (e.g., → vs ←, or [start] vs [end]) so the audience can read the trace at scroll speed",
"max_score": 10
},
{
"name": "Does not also install OpenTelemetry",
"description": "Does not add OpenTelemetry on top — the developer explicitly said no Langfuse/OTel for this demo. Adding it would require collector setup and isn't requested",
"max_score": 5
}
]
}evals
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skills
add-observability
add-persistence
add-rag
add-structured-output
add-token-budgeting
add-tool
cache-llm-calls
define-prompt
domain-model-subtask-pipeline
references
enable-prompt-caching
handle-agent-events
manage-state
migrate-from-0-x
model-planner-subtasks
persist-chat-history
query-sql-from-agent
scaffold-agent
snapshot-and-restore
test-koog-agents
trace-agent-internals
use-attachments
use-functional-agent
use-llm-node-variants
use-planner
wire-a2a
wire-acp-server
wire-ktor-server
wire-mcp-server
wire-spring-boot