> ## Documentation Index
> Fetch the complete documentation index at: https://agents.concierca.ch/llms.txt
> Use this file to discover all available pages before exploring further.

# Error Handling & Sources

> Recover from unknown benchmark/signal/channel errors via the legend, handle schema-cache mismatches, and use evidence links honestly.

## When a benchmark, signal, or channel is rejected

If a call fails because a benchmark name, `signal_type`, or channel is unknown:

<Steps>
  <Step title="Call vertical_legend">
    Re-read the live manifest — the benchmarks, signal catalog, and channels it advertises.
  </Step>

  <Step title="Use only advertised values">
    Pick the correct value from what the legend returns. Many tools also return an `available` / `error` list on rejection — use it.
  </Step>

  <Step title="Never guess a replacement">
    Do not invent a substitute string. If nothing advertised fits, say the requested value is not available rather than approximating it.
  </Step>
</Steps>

The **legend is the authoritative runtime manifest.** When in doubt about what exists, it decides — not memory, not a remembered value.

## Legend advertises a channel the client schema doesn't expose

<Warning>
  If `vertical_legend` advertises a channel (or signal) that your client's tool schema does not expose, treat it as a **schema-cache / registry mismatch — not** as proof the channel is absent.

  Reconnect or refetch `tools/list` to refresh the tool schema, then retry. Do not conclude the channel does not exist just because a stale client view is missing it.
</Warning>

The legend reflects the live server; the client's tool list can lag it. When they disagree, the legend is the truth and the client view is the thing to refresh.

## Sources and evidence links

* **`include_details=true` only when the user needs evidence.** It attaches source refs and enlarges responses — use it when the user wants source links, not by default.
* **Return the public `source_refs` that were returned.** Cite what the tool actually gave you.
* **Never fabricate a URL** and never claim a source that was not returned. If no source ref came back, say the evidence link is not available.

## Related

* [AI Operating Rules](/for-agents/vertical/operating-rules) — rule 1 (never invent) and the labeling rule.
* [Tool Reference](/for-agents/vertical/tools) — where `include_details` and `vertical_legend` are described.
* [Periods, Windows & Confidence](/for-agents/vertical/periods-and-confidence) · [Vertical tool list](/for-agents/vertical)