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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower. The description adds real value beyond that by describing the return shape in detail – one entry per day, ordered by date, with amount and average percentage – which matters specifically because no output schema exists.

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?

Four markdown sections for a three-parameter read tool, with heavy redundancy: the daily amount/average percentage return content is stated in the Overview, repeated in the 'What You Get' bullets, and repeated again in the Quick Start. It is front-loaded, but much of the text does not earn 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?

For a simple read-only date-range report with complete schema coverage, the definition covers inputs and return shape adequately. Minor gaps remain, such as timezone and how partial/missing days are handled, but nothing critical for correct invocation is missing.

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 baseline is 3. The Quick Start section restates 'from and to' as a date range and sandbox as an environment filter, but the ISO 8601 format details and the sandbox true/false semantics live entirely in the schema, so the description adds nothing new.

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 verb and resource: 'Returns commission earnings on the account for the given date range,' with the granularity (daily amounts and average percentage). It is distinguishable from sibling reports like post_analytics_report or get_bookings_hotels_sales_report by subject matter, though it never names a 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 'When to Use' section gives four scenarios (commission tracking, revenue analysis, financial reporting, dashboards), which qualifies as implied usage context. It offers no when-not-to-use guidance and never points to an alternative report tool, so an agent choosing among the many reporting siblings gets no routing help.

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