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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds scope (which dimensions and metrics apply) but says nothing about data freshness, default lookback behavior, or result shape beyond what the schema and output schema already provide.

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 sentences, both front-loaded with the essential information: scope/metrics first, then exclusions and redirects. There is no padding, and the negative guidance is placed where an agent will see it before committing to the call.

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 an output schema present and full parameter coverage, the description need not explain return values, and it correctly focuses on scope and routing. It is nearly complete, with only the vague 'sales or ads tools' redirect and unstated default date window keeping it below 5.

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 all 18 parameters (including enums for dimension, sort_by, and sort_order, plus date formats and pagination semantics) are already documented in the schema. The description's 'by date, store, page, source, or tag' phrase merely restates the dimension enum rather than adding syntax or interaction detail, 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?

The description names a specific resource (Amazon Brand Store analytics), the dimensions available (date, store, page, source, tag), and the metric set returned (views, visits, orders, units, sales, dwell time, bounce rate, new-to-store). It explicitly separates itself from account totals, ASIN/SKU sales, and ad campaign performance, so an agent can identify 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?

It gives explicit negative guidance ('Do not use for account sales totals, ASIN/SKU sales, or ad campaign performance'), which is the key routing signal against a large sibling list. However, the redirect is generic ('use sales or ads tools') rather than naming the concrete siblings such as get_sales_summary or get_campaign_performance, leaving the agent to guess the exact target.

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