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

Annotations already establish readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the key behavioral trait: this reads directly from the Amazon Ads API rather than the warehouse, and freshness may differ. It doesn't cover pagination, rate limits, or default result sizing, which the schema partially handles.

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?

Two sentences, no filler. The enumeration of entity families is front-loaded and the usage condition follows immediately; every clause earns its place and nothing is redundant.

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?

With an output schema present, return values need not be described, and the annotations cover the read-only safety profile. The description is complete enough to call the tool correctly, but for a 16-parameter tool sitting beside a similarly named sibling it should have clarified the boundary between the two live-entity tools.

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% across all 16 parameters, including the tricky profile_id default and the scope/entity_type relationships, so the structured data already carries the semantics. The description adds no syntax, format, or interaction detail on top of it, which is the expected baseline when the schema does the heavy lifting.

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 gives a specific verb (List) plus resource (Sponsored Products live entity state pulled directly from the Amazon Ads API) and enumerates the seven entity families covered. It is clear and actionable, though it never distinguishes itself from the near-identical sibling get_sponsored_ads_entities_live, which forces the agent to guess between them.

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?

"Use before write operations when warehouse snapshots may lag" gives an explicit trigger condition and the reason to prefer this live source over snapshot tools. It stops short of naming the competing live sibling or stating when-not to use it, so it is clear context without full exclusion guidance.

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