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

Annotations cover only the safety profile (readOnly, non-destructive), and the description adds substantial extra context: the data freshness horizon (22 Sep 2026), the fact that product coverage is partial (embedded products are only loaded listings, not full catalog), the meaning of itemCount, and the missing-result shape ({ data: null }).

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 action and lookup keys, then caveats. Every sentence carries information, though the density of caveats makes it slightly longer than strictly necessary.

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 burden of the return shape and does so (the null-data case, the embedded product completeness caveat, itemCount semantics, and the data freshness date). Nothing essential for calling it correctly 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 coverage is 75%, so id/country/productLimit are already documented. The description still adds meaning beyond the schema: id preferred over username, the username-missing edge case, and that embedded 'top stored products by units sold' relates to productLimit.

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 ('Fetch one Shopee shop') plus the two lookup modes, which clearly differentiates it from the sibling search tools (Shopee_search_shops, Shopee_search_products). An agent can select it without opening the 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 explicit guidance on which key to use ('use id when you have it') and warns that a username lookup can miss a shop that exists. Strong context, though it never names search_shops as the alternative for discovery-style queries.

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