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

# Protocol, Auth, and Errors

> Understand bearer auth, envelope semantics, and how Sports MCP Server signals ambiguity, partials, and failure modes.

# Protocol, Auth, and Errors

Sports MCP Server uses bearer auth and standard MCP request semantics.

## Auth

* requests require a bearer API key
* keys are product-scoped
* unauthorized requests fail before the tool layer runs

## Read response semantics correctly

<Tabs>
  <Tab title="Successful and complete">
    A normal successful response can be rendered directly, while still preserving `meta.sources` and `meta.agentHints.recommendedNextTools` for future turns.
  </Tab>

  <Tab title="Successful but partial">
    A partial result is still a success. It means one hybrid section was not safe or available enough to fill.
  </Tab>

  <Tab title="Ambiguous">
    Ambiguity means the server needs narrower scope. Use `meta.agentHints.disambiguationOptions` instead of silently picking a candidate.
  </Tab>

  <Tab title="Error">
    Errors represent malformed input, unsupported queries, upstream issues, rate or quota controls, or internal failures.
  </Tab>
</Tabs>

## Common envelope fields

* `meta.partial`
* `meta.missingSections`
* `meta.sources`
* `meta.crosswalkConfidence`
* `meta.agentHints.recommendedNextTools`
* `meta.agentHints.disambiguationOptions`
* `meta.limitations`
* `data`

## Common error categories

* `malformed_call`
* `unsupported_query`
* `ambiguous_scope`
* `no_data`
* `upstream_unavailable`
* `quota_or_rate_limit`
* `internal_error`

## Design rule

The server does not silently guess across provider namespaces. If the crosswalk is weak, it returns ambiguity or a partial result instead.

Crosswalk confidence is numeric:

* `0.90-1.00`: high confidence
* `0.60-0.89`: mixed confidence
* `0.01-0.59`: low confidence
* `null`: no safe crosswalk

## Read this next

* [Response Envelopes and Partials](/sports-mcp-server/concepts/response-envelopes-and-partials)
* [Access and API Keys](/sports-mcp-server/getting-started/access-and-api-keys)