docs: align skill guidance with reducer context docs

skills/concepts/SKILL.md

@@ -20,7 +20,7 @@ SpacetimeDB is a relational database that is also a server. It lets you upload a
 ## Critical Rules
 
 1. **Reducers are transactional.** They do not return data to callers. Use subscriptions to read data.
-2. **Reducers must be deterministic.** No filesystem, network, timers, or random. All state must come from tables.
+2. **Reducers must be deterministic.** Do not use filesystem, network, external clocks, or external random sources in reducers. Use `ReducerContext` for SpacetimeDB-provided timestamp and deterministic random values.
 3. **Read data via tables/subscriptions**, not reducer return values. Clients get data through subscribed queries.
 4. **Auto-increment IDs are not sequential.** Gaps are normal, do not use for ordering. Use timestamps or explicit sequence columns.
 5. **`ctx.sender` is the authenticated principal.** Never trust identity passed as arguments.

skills/csharp-server/SKILL.md

@@ -203,7 +203,7 @@ public partial struct TickTimer
 [SpacetimeDB.Reducer]
 public static void Tick(ReducerContext ctx, TickTimer timer)
 {
-    // timer row is auto-deleted after this reducer runs
+    // One-shot rows auto-delete after this runs; interval rows remain.
 }
 
 // One-time: fires once at a specific time

skills/rust-server/SKILL.md

@@ -201,7 +201,7 @@ pub struct TickTimer {
 
 #[spacetimedb::reducer]
 pub fn tick(ctx: &ReducerContext, timer: TickTimer) {
-    // timer row is auto-deleted after this reducer runs
+    // One-shot rows auto-delete after this runs; interval rows remain.
 }
 
 // One-time: fires once at a specific time

skills/typescript-server/SKILL.md

@@ -156,7 +156,7 @@ const tickTimer = table({
 
 export const tick = spacetimedb.reducer(
   { timer: tickTimer.rowType },
-  (ctx, { timer }) => { /* timer row auto-deleted after this runs */ }
+  (ctx, { timer }) => { /* one-shot rows auto-delete after this runs; interval rows remain */ }
 );
 
 // One-time: ScheduleAt.time(ctx.timestamp.microsSinceUnixEpoch + delayMicros)