get_sales_by_hour

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

The annotations already indicate a read-only operation, and the description adds value by disclosing timezone fallback behavior (merchant's local timezone, falling back to UTC with a note) and the permission requirement (PAYMENTS_R). This goes beyond the annotations and helps the agent understand operational nuances.

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 compact and front-loaded, using exactly two sentences to cover the core purpose, default behavior, timezone handling, and permission. There is no redundant 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?

Given the tool's simplicity, an output schema exists, and annotations cover safety, the description is largely complete. It covers the default date, timezone behavior, and required permission. Minor gaps remain regarding date format and what exactly constitutes 'gross sales', but these are not blockers for invocation.

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?

The schema has zero description coverage for the single 'date' parameter. The description implies it is a date and defaults to today, but does not specify the expected format (e.g., YYYY-MM-DD). It provides partial semantics but leaves ambiguity.

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 clearly states the tool returns gross sales bucketed by local hour-of-day for a single day, with a default of today. This distinguishes it from siblings like get_sales_summary or get_sales_by_employee by focusing on hourly granularity.

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 provides clear context: it is for a single day, defaults to today, and uses the merchant's local timezone. However, it does not explicitly mention alternatives or when-not-to-use this tool, 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.