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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real value by sketching the return payload (lift, adoption by ads/advertisers, example ads), explaining the doThis vs 'lower' split at the above/below-average boundary, and confirming exampleAdKeys are valid get_ad inputs.

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?

Three dense but front-loaded sentences; the primary return shape leads and the supporting keys follow. The semicolon-heavy middle sentence is slightly compressed but every clause carries 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?

There is no output schema, so the description must sketch the return shape, and it does – lift, adoption, example ads, doThis/'lower' grouping. The only gap is how the format parameter affects results, which is minor for a single optional filter.

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?

Only one parameter with 100% schema description coverage, so the schema already documents the format enum and its default. The description adds nothing about how the format filter changes the computed lift, which is the baseline 3 for schema-documented parameters.

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 precise verb and resource – returns lift per taxonomy value with adoption counts and example ads – and anchors it to a known artifact ('What to do now' block of Ad Radar). An agent can distinguish this from advertiser_hooks, search_ads and list_taxonomy 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?

Usage is implied through the 'What to do now' analytics-block mapping and the note that exampleAdKeys are consumable by get_ad, which hints at a call chain. However, it never states when to prefer this over siblings like search_ads or list_taxonomy, nor any exclusion or prerequisite.

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