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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds nothing beyond the word 'Read' – no cost, rate-limit, pagination, or attribution-behavior context – so it earns little credit even against the lower annotated bar.

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 words is short, but this is under-specification rather than conciseness; there is no front-loaded detail to be efficient with. Nothing in the sentence beyond the verb and a vague noun phrase.

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?

An output schema exists, so return values need not be described, but the five undocumented input parameters and the absent usage context leave the definition incomplete for a read tool with this many optional filters. It should at minimum distinguish the identity parameters and the date window.

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% across five parameters, including date_from, date_to, attribution, product_ref and product_name, and the description compensates for none of it. An agent has no idea what 'attribution' defaults to or how product_ref and product_name interact.

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?

Names a verb ('Read') and a resource ('per-ad funnel values'), which is more than a bare tautology, but 'funnel values' is undefined jargon that an agent cannot pin down without inference. It is distinguishable from siblings like products_get_actions or products_get_health only by the vague noun phrase, not by any stated scope.

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?

There is no when-to-use guidance, no mention of prerequisites, and no reference to any alternative tool. The agent is left to guess whether this is a breakdown query, a reporting export, or something adjacent to insights_pull_product_breakdowns.

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