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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds only the underlying endpoint path, with no note on result set size, pagination behaviour, or what a missing branch_number falls back to.

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?

Two short sentences, front-loaded with the metric and scope, with no filler. The raw endpoint line is of marginal use to an agent but does aid traceability.

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?

With no output schema, the description would need to hint at the return shape, but it never says what a 'top product' entry contains or whether the list is ranked or truncated. For a reporting tool with zero output schema, that leaves a real gap.

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 all four parameters are fully documented in the schema itself. The description only gestures at 'period' and 'branch number', adding no format or boundary detail beyond the schema, so the baseline 3 applies.

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 resource and metric: best-selling products over a period, optionally scoped to a branch. That clearly separates it from list_products or search_products, which do not rank by sales, though it never names those siblings explicitly.

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 analytics framing and 'period' scoping imply a reporting use case, but there is no explicit when-to-use, no prerequisites (account id, auth), and no discrimination against related reporting siblings like tillhub_sales_aggregate or tillhub_revenue_sum.

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