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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds valuable behavioral details: it returns exactly one skill, never raises a protocol error, returns an error object with fix guidance, and states 'Every call is read-only and idempotent, so after correcting the input it is always safe to retry.' This enriches the annotation data with concrete error behavior.

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 dense but each sentence serves a purpose: what it does, example I/O, differentiation from sibling, error behavior, and idempotency. It is front-loaded with the core action and stays information-dense without fluff.

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?

With only one parameter and rich annotations plus an output schema, the description still adds crucial context: automatic selection of the free skill, no plan required, error response format, and retry safety. It fully covers all operational aspects for an agent to invoke this tool correctly.

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?

The schema already covers the single param (slug) with a clear description and example. The tool description adds a concrete input example and shows the expected output structure, which reinforces parameter usage beyond the schema. Since schema coverage is 100%, baseline is 3; the example input/output pushes it to 4.

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 opens with a specific verb and resource: 'Load a product's free gateway skill with its complete instructions.' It clearly distinguishes this tool from the sibling get_full_skill by stating it returns only the free gateway skill and explicitly saying 'Not for the product's other skills: those are named and need get_full_skill with a skill_name.'

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 provides explicit usage context: 'Use when the caller wants usable instructions immediately.' It also names the alternative tool for other skills and even notes the plan requirement, giving clear when-to-use and when-not-to-use guidance.

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