Conciseness

The body is dense with non-obvious constraints ('4-byte big-endian uint32 length prefix + protobuf message bytes', 'Value is double-only… beyond 2^53 lose precision', 'package multi-targets net10/9/8/netstandard2.0/net472') and explains nothing Claude already knows. Every token earns its place, matching the lean-and-efficient 5 anchor.

Actionability

Guidance is fully executable: a copy-paste registration snippet ('services.AddSingleton<IAGUIEventStreamFormatter, ProtobufEventStreamFormatter>()'), concrete verify commands ('dotnet build from sdks/dotnet/; warnings are errors'), and exact file paths ('tests/AGUI.Abstractions.UnitTests/Compatibility/', 'PublicAPI.Unshipped.txt'). Per the instruction-only scoring note, absence of full code examples is not penalized when the guidance is this concrete, and it covers the common cases.

Workflow Clarity

The schema-first extension has a clear numbered sequence (extend shared .proto → add mapper case in ProtoEventMapper/ProtoMessageMapper) and an explicit 'How to verify' section with validation checkpoints (byte-parity cross-language tests, multi-TFM AOT build). It falls short of 5 because there is no explicit error-recovery loop describing what to do when byte-parity or the AOT build fails.

Progressive Disclosure

The ~95-line body is a well-sectioned overview of constraints, with exactly one clearly-signaled, one-level-deep reference — [references/wire-format.md] annotated with its scope ('framing, oneof mapping, Value bridge, negotiation parity') — which exists in the bundle with 9 focused sections. Content is appropriately split and easy to navigate, matching the 5 anchor.

Specificity

The description enumerates concrete, comprehensive actions — 'the protobuf codec, the SSE format, content negotiation, the JsonElement-to-protobuf Value bridge, or a brand new encoding' — each tied to named SDK artifacts, matching the top anchor of multiple specific concrete actions with comprehensive coverage. It is not 4 because there are no coverage gaps across the skill's scope.

Completeness

Both what and when are explicit: what is 'Add or modify a wire transport / event-stream encoding… while preserving Native AOT compatibility and byte-level wire compatibility', and when is given by concrete 'USE FOR:' triggers plus 'DO NOT USE FOR:' exclusions. This clearly matches the top anchor of explicit what AND when with concrete trigger phrases.

Trigger Term Quality

Good keyword coverage of natural domain terms ('SSE or protobuf framing', 'transport content negotiation', 'the JsonElement-to-google.protobuf.Value bridge', 'server formatter registration'), which a developer on this SDK would plausibly say. It falls short of the 5 anchor because the terms lean heavily on internal identifiers (AGUI.Formatting, AGUIResults.Events) and omit a few plainer phrasings a user might naturally use.

Distinctiveness Conflict Risk

A clear niche (wire transport/encoding in the AG-UI .NET SDK) with explicit conflict disambiguation: 'DO NOT USE FOR: adding a new wire event TYPE (use agui-dotnet-wire-types), writing tests (use agui-dotnet-integration-tests)'. Minimal conflict risk with sibling skills, matching the 5 anchor.