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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the description correctly focuses on behavior beyond that: what data comes back and the conditional expansion triggered by `color`. It doesn't cover failure modes (invalid slug/SKU, neither identifier provided), leaving a small behavioral gap for a zero-required-param lookup.

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 in the first clause, then the lookup keys, then the returned facets. Dense but every enumeration (decoration methods, size chart) maps to real tool output; only the long decoration-method list is slightly heavy.

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?

No output schema exists, so the description carries the return-value burden and does so thoroughly by enumerating the data fields. The remaining gap is the absence of any statement about precedence or behavior when both/neither of `slug` and `sku` are passed, given that no parameters are required.

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; the description earns more by explaining provenance (slug from search_catalog, SKU from a variant), the alternate lookup paths, and that `color` must match a name in `colors` and additionally returns that color's sizes with SKUs and availability.

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 ('Details for one product') and immediately distinguishes it from search_catalog by naming it as the source of the slug. It enumerates the returned facets (colors, sizes, size chart, fabric, decoration compatibility), so an agent can tell it apart from get_inventory or search_catalog without opening a 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?

Gives clear entry paths: lookup by slug from search_catalog or by any variant SKU, and explains the conditional use of `color` to expand the response. It doesn't state exclusions (e.g., use get_inventory for stock levels) or what happens when neither identifier is supplied, so guidance is strong but not fully explicit.

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