Problem
The skill_discovered NDJSON event is emitted once per skill every time the skill tool schema is registered — which happens once per step. This inflates downstream telemetry counts by a factor equal to the number of steps in the session.
Evidence
A recent execution bundled 2 skills into the workspace and ran 19 steps. Telemetry recorded:
skill_discovered: 38
step_start: 19
38 = 2 skills × 19 steps. Exact match.
Root cause
src/tool/skill.ts (SkillTool):
export const SkillTool = Tool.define("skill", async (ctx) => {
const skills = await Skill.all()
// Emit per-skill discovery events when descriptions are registered in tool schema
if (ctx?.sessionID) {
for (const skill of skills) {
Bus.publish(Session.Event.SkillDiscovered, {
sessionID: ctx.sessionID,
name: skill.name,
description: skill.description,
location: skill.location,
})
}
}
...
})The factory runs on every tool-schema registration, so each step re-publishes the full skill list.
Impact
- Downstream consumers (Session Control executor telemetry, dashboards) misreport "skills used" as a huge number — e.g. a 2-skill bundle appears as 38 "discoveries".
- Makes it hard to distinguish genuine skill-loading anomalies from normal multi-step runs.
- The event name suggests one-time discovery, which is what consumers assume.
Suggested fix
Emit skill_discovered once per (sessionID, skillName) — dedupe on the CLI side, either:
- Move the emission out of the tool factory into session start / skill-registry initialisation, OR
- Track emitted
(sessionID, name) pairs in a Set and skip duplicates, OR
- Rename the event to
skill_available (per-step) and add a new one-shot skill_loaded at session start — but this is a breaking schema change.
Option 1 is cleanest and matches the name's intent.
Version
Observed on @aictrl/cli@0.3.3. Same code path exists in 0.3.2.
Problem
The
skill_discoveredNDJSON event is emitted once per skill every time theskilltool schema is registered — which happens once per step. This inflates downstream telemetry counts by a factor equal to the number of steps in the session.Evidence
A recent execution bundled 2 skills into the workspace and ran 19 steps. Telemetry recorded:
38 = 2 skills × 19 steps. Exact match.
Root cause
src/tool/skill.ts(SkillTool):The factory runs on every tool-schema registration, so each step re-publishes the full skill list.
Impact
Suggested fix
Emit
skill_discoveredonce per (sessionID, skillName) — dedupe on the CLI side, either:(sessionID, name)pairs in aSetand skip duplicates, ORskill_available(per-step) and add a new one-shotskill_loadedat session start — but this is a breaking schema change.Option 1 is cleanest and matches the name's intent.
Version
Observed on
@aictrl/cli@0.3.3. Same code path exists in 0.3.2.