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

Beyond the annotations (readOnly/idempotent/non-destructive), it discloses the error contract in detail: no protocol errors are raised, failures come back as {"error": ...} with a fix hint, and retrying after correction is safe. It also flags the PREMIUM/license gating, which the annotations do not convey and which materially affects whether a call will succeed.

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?

Front-loaded with the core purpose and the usage decision, and most sentences carry distinct information (alternatives, error contract, retry safety). The inline request/response example is partly redundant with the existing output schema, adding a little length without new semantics.

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?

Covers purpose, chaining (slug comes from list_products, skill_name from its skills array), sibling routing, license gating, and failure/retry behavior. With an output schema present, the return-value explanation is a bonus rather than a gap, so an agent has everything needed to call it 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?

Schema coverage is 100%, so the baseline is 3, but the description adds a concrete worked example ({"slug": "inbox-assistant", "skill_name": "Zero Sweep"}) that shows the expected value shape and the product-plus-skill pairing. It stops short of saying how skill_name matching behaves on near-misses, so not a 5.

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 ('Load one paid skill's complete instructions from a product') and immediately scopes it to exactly one named skill. It explicitly distinguishes itself from get_free_skill and get_full_product, so an agent can pick correctly without opening schemas.

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?

Gives an explicit when-to-use ('Use when the caller wants one specific paid skill') plus two named exclusions with their alternatives: the free gateway skill goes to get_free_skill, and the full set goes to get_full_product. Nothing is left to inference.

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