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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context: the data comes from the regulator's report, includes sample size and as-of date, and is historical rather than predictive. This clarifies the nature and limitations of the returned value.

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 sentences with no filler: the first states the result and its components, the second scopes availability, and the third prevents misuse. The most important information is front-loaded.

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 output schema, the description still explains the key return components—share, sample size, source, and as-of date—and the supported state set. For a two-parameter read-only lookup, this is sufficient for an agent to select and invoke the tool correctly.

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%, so the baseline is 3. The description reinforces that the insurer parameter refers to one specific insurer and that the state must be one of the listed venues, but it adds no format or value details beyond what the schema already provides.

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 names a specific operation—returning the overturned-share for one insurer in one state—and lists the output elements including sample size, source, and as-of date. It also disambiguates from sibling tools by clarifying this is not a ranking, comparison, or prediction.

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?

The description gives clear usage context by listing supported states and specifying that this is one insurer's own historical rate, not a comparison or prediction. It does not explicitly name sibling alternatives such as 'use get_hospital_rate for comparisons,' so routing guidance could be stronger.

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