Conciseness

The ~40-line body is lean and entirely package facts: "Language: C++", "Real network support: yes", "Runtime profiles: `javascript-quickjs`, `python-pyodide`". No concept Claude already knows is explained, no padding, and every token carries package-specific information. It clearly matches the anchor 5 example of lean, efficient content.

Actionability

The Core Pattern gives real C++ syntax ("axllm::agent("question:string -> answer:string")", "helper.forward(llm, {...})") plus concrete symbol names in the API Surface section and directives like "Use `no-key` examples for deterministic local checks". It is not a 5 because the snippet is not copy-paste ready — `llm` is undefined, no includes or setup are shown — which is only partially mitigated by the pointer to start from package examples.

Workflow Clarity

As a single-purpose reference skill under 50 lines with well-organized sections it would qualify for 5 under the simple-skill exception, but there are minor clarity gaps: the "When To Use" bullet "Explain that generated packages are not TypeScript transpilers; they adapt the Ax runtime contract" is a behavioral instruction misplaced in a trigger list, and no first concrete step (which example to open, which manifest to check) is sequenced.

Progressive Disclosure

Structure is good: the body stays an overview (core pattern, compact API list) and the Package Facts section clearly signals where the deep material lives ("API.md and axir-api.json", "axir-capabilities.json", "examples/"). It falls short of 5 because those references are bare backtick names with no resolvable path or link — relative to the package is only implied — leaving minor navigation ambiguity.

Specificity

The description names the domain ("writing C++ code with `axllm`") and lists several concrete capability areas ("RLM executor loops, AxCodeRuntime sessions, runtime envelopes, process runtimes, and optional runtime profiles"), giving broad but not fully action-oriented coverage. It does not reach a 5 because the only action verb is "writing" — the items are topics rather than specific actions the skill performs, and it fits anchor 4 (several specific items, minor gaps) better than anchor 3 (only 1-2 concrete actions).

Completeness

The "when" is fully explicit ("Use when writing C++ code with `axllm` for..."), but the "what" is never directly stated — the description opens with the trigger clause and only implies the skill's purpose through the enumerated topics. This sits between anchor 2 (only 'when' present) and anchor 4 (both explicit); the enumerated areas partially convey the what, warranting the midpoint.

Trigger Term Quality

Key natural terms for this niche are present: "C++", "axllm", "AxCodeRuntime", "runtime profiles", "process runtimes", "RLM executor loops". It stays at 4 rather than 5 because a few related trigger terms (e.g. ProcessCodeRuntime, actor-code sessions) appear only in the body, and no synonyms or extensions are covered.

Distinctiveness Conflict Risk

The description is anchored to highly specific identifiers (`axllm`, AxCodeRuntime, RLM) that only apply to this package, giving it a clear niche with distinct triggers and minimal conflict risk with any other skill.