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

The description adds significant behavioral context beyond the annotations. It details error handling behavior ('never raises a protocol error — it returns {"error": ...}') and confirms idempotency and read-only nature. All behavioral traits are consistent with annotations, and no contradictions exist.

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 concise, well-organized, and front-loaded with the core purpose. It uses short paragraphs with clear sections: purpose, example, usage guidelines, error handling. Every sentence adds value without redundancy.

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?

Given the tool's simplicity (single parameter, clear output schema), the description covers all needed aspects: purpose, input format, return value structure, usage boundaries, error handling, and behavioral guarantees (read-only, idempotent). Nothing essential is missing.

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 baseline is 3. The description adds a concrete example input and output ({"slug": "brand-voice"} returns specific fields), which clarifies the parameter's purpose and expected format. This extra semantic context raises the score above baseline.

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 the tool loads a product's free gateway skill with complete instructions. It uses a specific verb ('load') and resource ('free gateway skill'), and distinguishes from siblings by mentioning that other skills require 'get_full_skill'. This provides excellent purpose clarity.

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 states when to use this tool ('Use when the caller wants usable instructions immediately') and when not to ('Not for the product's other skills'). It directly contrasts with the sibling 'get_full_skill' and explains that the other tool requires a paid plan. This provides clear usage guidelines with specific alternatives.

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