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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, and the description usefully confirms that no writes occur and that campaign_id scopes the result to one campaign. It adds no information about time windowing (days), result volume limits (max_findings), or output rendering, so the added behavioral context is modest.

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 dense sentences that lead with what is reported and then with what is proposed, so the most important facts come first. The trailing 'Tools revision: d80f65c0.' is metadata noise that does not help an agent decide or call anything.

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?

Safety profile is covered by annotations and return values by the output schema, so the core gaps are the unexplained behavioral parameters (days, detail, render, max_findings) and the absence of any note on result size or pagination. Adequate to call, but an agent would be guessing about the window and output shape.

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 six parameters, so the description must carry the load. It explains only campaign_id ('digits', narrows to one campaign) and leaves days, detail, render, max_findings, and customer_id entirely uninterpreted; the enum values for detail and render are never tied to what they change in the report.

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 verb and resource ('Report every responsive-search-ad headline and description') and enumerates the exact payload: BEST/GOOD/LOW labels, ad strength, counts, pinning, and last creative change. It also implicitly distinguishes itself from create_responsive_search_ad and update_ad_status by positioning those as suggestions rather than actions.

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?

Makes the use case clear: audit RSA assets and see a proposed replacement expressed as suggested create_responsive_search_ad and update_ad_status calls, with the explicit exclusion 'it creates and pauses nothing.' It lacks a direct 'use X instead when...' statement, so it stops just short of full when/when-not guidance.

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