Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint. The description adds 'Free, read-only' and 'Path-traversal protected', providing security context beyond annotations. No contradictions are present.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, each earning its place: first states the function, second gives the type constraint, third gives the source for filenames, and the fourth covers security and cost. It is front-loaded and has zero waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers what the tool does, when to use it, and security. With 2 parameters fully documented in schema and annotations covering safety, the description is nearly complete. It lacks explicit error or return format details, but for a simple read operation this is acceptable.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and both parameters have descriptions. The description adds extra guidance: for skill_name it reiterates the type constraint, and for reference_path it adds the instruction about finding filenames via the router table, which adds value beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it loads one reference file from a register-type skill's references folder. The verb 'Load' and resource 'reference file' are specific. It distinguishes from other tools by explicitly contrasting with foundations and methodologies being inline content only.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Only register-type skills have references/' and directs the agent to find valid filenames in the parent SKILL.md router table. This gives clear when-to-use and when-not-to-use guidance, effectively differentiating from sibling tools like load_skill and list_skills.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.