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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds the meaningful detail that results come from stored data only, but says nothing about freshness, ordering, or what an empty result means.

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 short clauses, front-loaded with the resource and immediately qualified by "Stored data only". No wasted wording, though the parenthetical field list could be phrased more cleanly.

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 no input parameters and no output schema, the description carries the return-shape burden and does list the fields returned, which is the right compensation. Only the lack of result-ordering/freshness detail keeps it from being fully complete.

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?

The tool takes zero parameters, so the baseline is 4; there are no arguments whose meaning needs explaining. The description correctly implies no filtering inputs are available.

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?

Uses a specific verb ("List") plus the exact resource (Google Ads accounts connected to this business in AnvilAds) and enumerates the returned fields (customer id, name, currency, status). It is clear what the tool does, though it does not explicitly contrast itself with siblings such as get_business_profile or list_campaigns.

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?

"Stored data only" implies this is a cached/local read rather than a live Google Ads fetch, which helps set expectations. However, there is no explicit when-to-use guidance or statement about when an agent should prefer a sibling tool like get_business_profile.

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