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

The description adds error handling behavior beyond annotations: 'this tool never raises a protocol error — it returns {"error": ...}'. It also confirms idempotency and read-only nature, which aligns with annotations. No contradiction.

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—three short paragraphs covering purpose, example, usage guidelines, and error handling. Every sentence is necessary and well-structured, with no 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?

The description covers purpose, usage, parameters, error handling, and retry safety. The output schema likely handles return structure details, so the description is complete for the tool's complexity. An agent has all necessary information to select and invoke the 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 input schema already provides 100% coverage with clear descriptions for both parameters. The description adds value with a typical input example and clarifies that skill_name selects one named skill. This justifies moving above the baseline of 3.

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 one paid skill's complete instructions from a product. It provides a concrete example and explicitly distinguishes from sibling tools get_free_skill and get_full_product, making the purpose unambiguous.

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: 'Use when the caller wants one specific paid skill.' It also tells when not to use: 'Not for the free gateway skill... and not for every skill at once.' This provides clear guidance on alternatives.

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