fix: return object-shaped structuredContent from list tools

README.md

@@ -636,6 +636,8 @@ Structured repository results use compact DTOs rather than raw REST objects. Rel
 
 For `get_repository_tree`, `list_gists`, `get_gist`, `create_gist`, and `update_gist`, gist results retain file names, contents, sizes, language/type information, timestamps, visibility, and compact owner profiles, while omitting API/node and Git transport URLs. Tree entries omit their derivable API URLs. Create/update gist results contain the gist ID and HTML URL. Modern JSON text and structured content serialize the same compact result. Older or unknown protocol versions retain byte-for-byte legacy text without an output schema or structured content.
 
+List-returning tools `list_commits` and the `pull_request_read` methods `get_files`, `get_commits`, `get_reviews`, and `get_comments` expose their arrays inside a named object field (`commits`, `files`, `reviews`, `comments`) because MCP requires `structuredContent` to be a JSON object rather than a top-level array. Modern JSON text serializes the same object; older and unknown protocol versions keep the bare array text unchanged.
+
 The issue metadata (`list_issue_types`, `list_issue_fields`), comment (`add_issue_comment`, `update_issue_comment`), dependency (`issue_dependency_read`, `issue_dependency_write`), and duplicate-detection (`find_duplicate`) tools provide typed `outputSchema` and `structuredContent` for negotiated supported protocol versions `2026-07-28` or newer. Older or unknown protocol versions retain the same text responses without these fields. Tool errors do not return structured content. Dependency and duplicate-detection tools retain their existing feature gates.
 
 For negotiated supported protocol versions `2026-07-28` or newer, the consolidated Actions tools (`actions_list`, `actions_get`, `actions_run_trigger`) return structured objects with a `method` discriminant and a method-specific typed field; JSON text contains the same compact projection. Workflow, job, and artifact projections omit API/hypermedia URLs while retaining browser links and useful identifiers, states, timestamps, and usage durations. Run usage lists billable runner environments in deterministic name order. Older and unknown-protocol text responses remain unchanged; `get_job_logs` retains its typed content, URL, or failed-job collection variants.

docs/typed-tool-schemas.md

@@ -63,6 +63,11 @@ malformed versions also retain the legacy text result. Normal `Inventory.Registe
 protocol era is already known before server construction, such as a stateless
 request-scoped server.
 
+The MCP schema for `structuredContent` is an object, so a typed output must not
+be a top-level array. Wrap list results in a named field (for example
+`ListCommitsOutput{Commits: [...]}`) and give the output schema the matching
+object shape; the handler text may still be a bare array for legacy clients.
+
 If a handler intentionally returns non-JSON text or content blocks, set
 `PreserveHandlerContent` in `TypedSchemaOptions`, or call
 `inventory.PreserveToolHandlerContent(ctx)` from the handler middleware for