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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely new behavioral detail: the default reporting window is today in UTC and results are aggregated per seller rather than returned as raw documents.

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?

A single sentence that front-loads the resource and scope, with the default window and endpoint appended compactly. No filler and nothing that could be cut without losing information.

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?

For a read-only, three-parameter aggregation endpoint with no output schema, the description covers scope, grouping, defaults, and the filtering option. A brief note on the shape of the returned totals would be the only useful addition.

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 67% and the two undocumented aspects are covered by the description: 'default: today, UTC' explains what happens when from/to are omitted, and 'or for one user' gives user_id its meaning (filter results to a single seller), which the schema leaves bare.

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 verb: 'Sales and tax subtotal per seller' over a date range or for one user, plus the underlying endpoint. It is distinguishable from the sibling bsale_sales_summary by its per-seller grouping, though it never names that sibling 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 description implies usage through the two modes (date range vs. single user) and gives the default range of today (UTC), but it never states when to reach for this over bsale_sales_summary or what to do if both from and to are omitted together. Usage is inferable, not spelled out.

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