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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description only needs to add context — and it does, disclosing the Pro-token gating, the full-vs-pointer return behavior, and the markdown output format. That is genuine information beyond the structured fields.

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 opening sentence is well front-loaded, but the body is a single massive semicolon-delimited run-on covering 20 ids with no formatting or line breaks. Every item carries useful content, yet the density makes it hard to scan and the last Pro paragraph is buried.

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?

There is no output schema, so the description must describe returns — and it does (markdown file, plus the /api/skills redirect for non-token Pro access). Combined with the exhaustive id list, an agent has what it needs, though pagination/size limits are unmentioned.

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%, so the baseline would be 3, but the description goes further by explaining what each id value actually contains (e.g., 'composition (page containers, dashboards, marketing sections…)'), which adds selection meaning beyond the flat enum listed in 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?

States a specific verb and resource — 'Get one Arc skill file as markdown' — and immediately frames the content domain as 'rules for building with Arc'. An agent can distinguish this from siblings like get_component or search_components without opening any schema.

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 per-id breakdown effectively tells the agent when each skill file is the right choice (e.g., INSTRUCTIONS for agents.md/claude.md, checklist for pre-finish review loops). What's missing is any explicit statement of when NOT to use this tool or a pointer to sibling alternatives, so it falls short of the 5 bar.

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