Top advertisers and ad publishers

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

Annotations already declare readOnlyHint and openWorldHint, so the safety bar is covered. The description adds real behavioral context beyond that: the app_id mode returns page, rank and sov, and the notable gotcha that 'Facebook' is rejected here but valid on network_analysis. No rate-limit or auth detail, but for a read tool this is solid.

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 tight sentences, front-loaded with the core purpose before the mode switch and the vocabulary caveat. Every sentence is load-bearing and none restate the schema.

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 14-parameter tool with no output schema, the description covers purpose, the two operating modes, key return shape (page, rank, sov), and a vocabulary pitfall. Remaining details (pagination limits, field selection, dry_run) are handled in the schema, so the definition is nearly complete but not exhaustive.

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?

With 71% schema coverage the schema does most of the work, giving a baseline of 3. The description earns the extra point by explaining the semantics of role (advertiser=buying vs publisher=showing) and app_id (single-app rank lookup) rather than just restating names.

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 and verb: a share-of-voice leaderboard scoped to a network and category. It clarifies both modes (full board vs single-app position) and defines role semantics, so the agent knows exactly what it produces. It does not explicitly differentiate itself from the sibling sensortower_top_publishers, which is the one gap keeping this from a 5.

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?

Gives clear when-to-use guidance: role=advertiser for buyers, role=publisher for publishers, and supply app_id to switch from whole-board to single-app lookup. It also flags the per-endpoint network vocabulary constraint. No explicit when-not here, but the alternatives are well covered.

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