feat(github): add typed Copilot and UI outputs

docs/feature-flags.md

@@ -237,23 +237,23 @@ as output formatting) won't appear here.
   - `path`: The relative path of the file to comment on (string, required)
   - `pullNumber`: The pull request number (number, required)
   - `repo`: Repository name (string, required)
-  - `side`: The side of the diff to comment on (LEFT or RIGHT, optional) (string, optional)
+  - `side`: The side of the diff to comment on (optional) (string, optional)
   - `startLine`: The start line of a multi-line comment (optional) (number, optional)
-  - `startSide`: The start side of a multi-line comment (LEFT or RIGHT, optional) (string, optional)
-  - `subjectType`: The subject type of the comment (FILE or LINE) (string, required)
+  - `startSide`: The start side of a multi-line comment (optional) (string, optional)
+  - `subjectType`: The subject type of the comment (string, required)
 
 - **add_pull_request_review_comment_reaction** - Add Pull Request Review Comment Reaction
   - **OAuth Challenge Scopes**: `repo`
   - `comment_id`: The numeric pull request review comment ID. Use the number from a #discussion_r... anchor, not the GraphQL thread node ID (PRRT_...). (number, required)
-  - `content`: The emoji reaction type (+1, -1, laugh, confused, heart, hooray, rocket, or eyes) (string, required)
+  - `content`: The emoji reaction type (string, required)
   - `owner`: Repository owner (username or organization) (string, required)
   - `repo`: Repository name (string, required)
 
 - **create_pull_request_review** - Create Pull Request Review
   - **OAuth Challenge Scopes**: `repo`
   - `body`: The review body text (optional) (string, optional)
   - `commitID`: The SHA of the commit to review (optional, defaults to latest) (string, optional)
-  - `event`: The review action to perform (APPROVE, REQUEST_CHANGES, or COMMENT). If omitted, creates a pending review. (string, optional)
+  - `event`: The review action to perform. If omitted, creates a pending review. (string, optional)
   - `owner`: Repository owner (username or organization) (string, required)
   - `pullNumber`: The pull request number (number, required)
   - `repo`: Repository name (string, required)
@@ -300,7 +300,7 @@ as output formatting) won't appear here.
 - **submit_pending_pull_request_review** - Submit Pending Pull Request Review
   - **OAuth Challenge Scopes**: `repo`
   - `body`: The review body text (optional) (string, optional)
-  - `event`: The review action to perform (APPROVE, REQUEST_CHANGES, or COMMENT) (string, required)
+  - `event`: The review action to perform (string, required)
   - `owner`: Repository owner (username or organization) (string, required)
   - `pullNumber`: The pull request number (number, required)
   - `repo`: Repository name (string, required)
@@ -341,7 +341,7 @@ as output formatting) won't appear here.
   - `owner`: Repository owner (username or organization) (string, required)
   - `pullNumber`: The pull request number (number, required)
   - `repo`: Repository name (string, required)
-  - `state`: The new state for the pull request (open or closed) (string, required)
+  - `state`: The new state for the pull request (string, required)
 
 - **update_pull_request_title** - Update Pull Request Title
   - **OAuth Challenge Scopes**: `repo`
@@ -402,8 +402,8 @@ as output formatting) won't appear here.
   - `confidence_threshold`: Minimum similarity threshold a candidate must meet to be returned; higher values are stricter. When omitted, the API's high-precision default is used. The scale is defined by the API, so no client-side bounds are enforced. (number, optional)
   - `issue_number`: The number of the existing issue to find duplicates for (number, required)
   - `owner`: The owner of the repository (string, required)
-  - `page`: Page number for pagination (min 1). An explicit 0 is forwarded to the API as-is rather than being replaced with 1. (number, optional)
-  - `perPage`: Results per page for pagination (min 1, max 100). An explicit 0 is forwarded to the API as-is rather than being replaced with 30. (number, optional)
+  - `page`: Page number for pagination (min 1) (number, optional)
+  - `perPage`: Results per page for pagination (min 1, max 100) (number, optional)
   - `repo`: The name of the repository (string, required)
 
 ### `thread_resolution_reason`

docs/typed-tool-schemas.md

@@ -1,9 +1,9 @@
 # Typed tool schemas
 
 Typed tool registrations use concrete Go input and output types with the MCP
-Go SDK's `mcp.AddTool` path. The SDK infers schemas when the tool definition
-does not provide them, validates arguments before the handler runs, and
-validates typed output. Keep business rules that JSON Schema cannot express
+Go SDK's `mcp.AddTool` path. Inventory infers missing schemas and validates
+arguments against the cached input schema before the handler runs; the SDK
+adapts and validates typed output. Keep business rules that JSON Schema cannot express
 in the handler or a preflight callback.
 
 Input inference unwraps one pointer level, matching the SDK's object input
@@ -31,13 +31,13 @@ schemas; do not mutate the returned pointers.
 
 When compatibility requires a broader runtime input contract than the one
 advertised to clients, provide `ValidationInputSchema`. The tool's declared
-`InputSchema` remains visible while the SDK validates calls against the
+`InputSchema` remains visible while inventory validates calls against the
 runtime-only schema. Use `Preflight` for checks that need raw arguments or
 request dependencies before typed decoding; it may return a derived context
 for the handler. Input normalizers are only for compatibility transformations,
 not a replacement for schema validation.
 
-The SDK applies defaults from the runtime input schema before decoding. If an
+Inventory applies defaults from the runtime input schema before decoding. If an
 omitted field must remain omitted, build the runtime schema with
 `inventory.CloneSchemaWithoutDefaults` before applying validation-only
 changes. Use `inventory.CloneSchema` when deriving other runtime-only schema
@@ -46,6 +46,14 @@ subschemas. Default removal visits each child once per parent. The advertised
 schema can retain its defaults; the constructor caches the runtime schema
 without mutating either caller-owned schema.
 
+Availability and authorization guards run before preflight, normalization,
+and input validation. A guard or preflight result is passed through the
+registered SDK handler without decoding the original arguments or invoking
+user code, so the SDK still finalizes multi-round-trip results with
+`resultType: "input_required"` (or `"complete"`). The permissive SDK input
+envelope used for this handoff is never advertised and does not replace the
+original validation schema for real calls.
+
 The output schema and `structuredContent` are exposed only for a negotiated,
 SDK-supported protocol version `2026-07-28` or later. Unknown versions are
 treated as legacy, including unsupported future dates; older, absent, and
@@ -58,4 +66,7 @@ request-scoped server.
 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
-request-dependent output such as CSV.
+request-dependent output such as CSV. This is for intentional non-DTO responses
+such as resources, errors, or CSV; ordinary declared structured success must
+retain shared DTO serialization, with modern JSON text equal to
+`structuredContent`, even when legacy handler text was a plain mutation message.

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/microcosm-cc/bluemonday v1.0.27
 	github.com/modelcontextprotocol/go-sdk v1.8.0
 	github.com/muesli/cache2go v0.0.0-20221011235721-518229cd8021
+	github.com/segmentio/encoding v0.5.4
 	github.com/shurcooL/githubv4 v0.0.0-20260209031235-2402fdf4a9ed
 	github.com/shurcooL/graphql v0.0.0-20240915155400-7ee5256398cf
 	github.com/spf13/cobra v1.10.2
@@ -32,7 +33,6 @@ require (
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
 	github.com/sagikazarmark/locafero v0.11.0 // indirect
 	github.com/segmentio/asm v1.1.3 // indirect
-	github.com/segmentio/encoding v0.5.4 // indirect
 	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
 	github.com/spf13/afero v1.15.0 // indirect
 	github.com/spf13/cast v1.10.0 // indirect