download_sales_report

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it returns parsed rows (not raw file bytes), covers specific metrics, and implies decompression via the max_bytes parameter. It doesn't mention pagination or row limits, but the schema covers max_rows. This is solid but not exhaustive.

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?

The description is two sentences with no filler. The first sentence states the action and output format; the second lists covered metrics and points to the sibling for valid combinations. Every sentence earns its place.

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?

The tool has an output schema, 100% parameter coverage, and annotations covering safety, so the description doesn't need to explain return values or safety. It covers the report content and points to the sibling for valid combinations. The only minor gap is not explicitly stating that this is for App Store Connect sales reports, but the sibling names and vendor_number parameter make that clear.

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 the schema already documents all 8 parameters. The description adds context about the report content (units sold, proceeds, etc.) and points to list_sales_report_types for valid combinations, which helps with report_type/report_sub_type semantics. However, it doesn't add much beyond the schema for individual parameters, so baseline 3 is appropriate.

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 states a specific verb ('Download') and resource ('Sales and Trends report'), and clarifies the output format ('parsed rows'). It also lists the metrics covered, which distinguishes it from finance reports and other report tools. The reference to list_sales_report_types for valid combinations further disambiguates it from siblings.

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 clearly indicates when to use this tool: to download a Sales and Trends report and get parsed rows. It points to list_sales_report_types for valid combinations, which is a form of alternative guidance. However, it does not explicitly state when not to use it (e.g., for finance reports or report instances), so it falls short of a 5.

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