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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the 5000-row cap and the tenant-scoping constraint. It stops short of describing pagination or return shape, but the cap is a meaningful trait.

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?

Front-loaded purpose sentence, then labeled sections (REQUIRED, DATE PARAMS, EXAMPLE) that make the critical constraints scannable. The example earns its place by demonstrating the required-parameter combination and date format.

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, annotation-covered tool with no output schema, the description supplies what the schema omits: required params, naming caveat, row cap, and sibling routing. Only the connection_context parameter and any row-shape expectations are unaddressed.

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 0% and all five params are nullable with defaults, so the schema implies nothing is required. The description compensates strongly: it declares the actual required set (date_from, date_to, and one of ad_account_id/product_id), warns against the start_date/end_date naming trap, and supplies a concrete call example. connection_context is left unexplained, keeping this from a 5.

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 (raw insight rows) with its scope (authenticated tenant) and an explicit cap (5000), then contrasts directly with the sibling query_overview as 'the main read path.' An agent can tell this apart from the other insights_* tools 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?

Explicitly routes usage: 'Use for debugging or detail drilldown; query_overview is the main read path.' This names both the when-to-use and the preferred alternative for the common case, leaving nothing to inference.

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