m04-zero-cost

CRITICAL: Use for generics, traits, zero-cost abstraction. Triggers: E0277, E0308, E0599, generic, trait, impl, dyn, where, monomorphization, static dispatch, dynamic dispatch, impl Trait, trait bound not satisfied, 泛型, 特征, 零成本抽象, 单态化

Quality

77%

Does it follow best practices?

Impact

—

No eval scenarios have been run

Securityby

Passed

No known issues

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tessl review fix ./skills/m04-zero-cost/SKILL.md

Quality

Content

64%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This is a well-structured decision framework for Rust's generics and trait system that excels in conciseness and organization. Its main weakness is that it functions more as a conceptual guide than an actionable troubleshooting skill — the 'Error → Design Question' approach is philosophically sound but lacks concrete resolution workflows with validation steps. The referenced related skills (m05, m07, m09, m10) are not backed by bundle files, limiting progressive disclosure effectiveness.

Suggestions

Add concrete, executable examples for resolving each error code (E0277, E0308, E0599, E0038) showing before/after code with the specific fix applied

Include a validation step in the workflow, e.g., 'After changing dispatch strategy, verify with `cargo check` and confirm no new trait bound errors'

Provide bundle files or clarify file paths for referenced skills (m05-type-driven, m09-domain, etc.) to support progressive disclosure

Dimension	Reasoning	Score
Conciseness	The content is lean and efficient throughout. It assumes Claude understands Rust's type system and doesn't waste tokens explaining what generics or traits are. Every section delivers decision-relevant information in compact tables and concise code snippets.	3 / 3
Actionability	The syntax comparison provides executable Rust code examples, and the error code reference gives concrete quick fixes. However, the skill is more of a decision framework than executable guidance — it tells Claude what questions to ask rather than providing copy-paste solutions for specific scenarios. The 'Trace Up/Down' sections reference other skills (m09-domain, m05-type-driven) without concrete resolution steps.	2 / 3
Workflow Clarity	The 'Thinking Prompt' section provides a clear decision sequence, and the 'Trace Up/Down' sections show diagnostic flow. However, there are no validation checkpoints or feedback loops — when encountering errors like E0277, the guidance is to 'ask' questions rather than providing a concrete fix-validate-retry workflow. For a skill triggered by compiler errors, explicit resolution steps with verification would strengthen this.	2 / 3
Progressive Disclosure	The content is well-structured with clear sections and tables, and references related skills (m05-type-driven, m09-domain, m10-performance, m07-concurrency). However, there are no bundle files to support these references, and the references use internal IDs without clear file paths. The content is moderately long but appropriately organized for inline consumption.	2 / 3
	Total	9 / 12 Passed

Description

89%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

This description excels at trigger term coverage and distinctiveness, with an impressive range of natural keywords including error codes and multilingual terms. Its main weakness is the lack of specific concrete actions—it tells Claude the topic area but not what specific tasks it can perform (e.g., 'resolve trait bound errors', 'refactor generic code', 'convert between static and dynamic dispatch'). The format is functional but reads more like a tag list than a capability description.

Suggestions

Add 2-3 concrete actions describing what the skill does, e.g., 'Resolves trait bound errors, implements generic types, refactors between static and dynamic dispatch, and explains monomorphization behavior.'

Dimension	Reasoning	Score
Specificity	The description names the domain (Rust generics, traits, zero-cost abstraction) and implies actions like resolving specific error codes, but does not list concrete actions (e.g., 'implement trait bounds', 'resolve type mismatch errors', 'refactor to use dynamic dispatch').	2 / 3
Completeness	The description explicitly answers both 'what' (generics, traits, zero-cost abstraction) and 'when' (via the 'CRITICAL: Use for...' and 'Triggers:' clauses that list specific error codes and keywords). The trigger guidance is explicit and actionable.	3 / 3
Trigger Term Quality	Excellent coverage of natural trigger terms including Rust error codes (E0277, E0308, E0599), common keywords users would type (generic, trait, impl, dyn, where, monomorphization, static dispatch, dynamic dispatch, impl Trait, trait bound not satisfied), and even Chinese equivalents (泛型, 特征, 零成本抽象, 单态化).	3 / 3
Distinctiveness Conflict Risk	Highly distinctive with Rust-specific error codes (E0277, E0308, E0599) and domain-specific terms like monomorphization, static/dynamic dispatch, and trait bounds. This is unlikely to conflict with other skills unless there are multiple Rust-specific skills, and even then the error codes provide clear differentiation.	3 / 3
	Total	11 / 12 Passed

Validation

90%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 10 / 11 Passed

Validation for skill structure

Criteria	Description	Result
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	10 / 11 Passed

Repository: actionbook/rust-skills
Commit: fa60f79

Reviewed: 29 days ago

Table of Contents

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