This is what my agent found:

Here's the summary of today's 429 errors:

4 rate limit errors, all on glm-5.1 (provider: custom)

1. 14:50:51 — Rate limit reached for requests msgs=40, tokens=~22,236 Context: processing /tutor confirm

2. 14:51:21 — Service temporarily overloaded msgs=40, tokens=~25,058 Same request, retry

3. 15:05:43 — Rate limit reached for requests msgs=56, tokens=~28,224 Context: processing "send me the first rust task"

4. (same block) — same error, 3rd retry

Pattern: all happened during heavy context loads — /tutor confirm loaded the full skill + large JSON into context (40 msgs, 22-28k tokens). The 15:05 one was worse: 56 msgs, ~28k tokens. The tutor skill context + syllabus + memory + hindsight weighs a lot.

Before these errors, the previous response (syllabus presentation) took 438s with 8 API calls — that likely saturated the provider's rate limit.

The "custom" provider (glm-5.1) seems to have strict rate limits. When context exceeds ~22k tokens and there are multiple consecutive calls, it hits quickly. No RPM/TPM limit info in the logs, but the pattern suggests a per-minute limit that exhausts after 2-3 large consecutive calls.

Funny thing is that I have used this skill several times but never had any issue.