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

With annotations already declaring readOnlyHint=true, the description adds value by explaining the data is a composite of three place-intelligence layers and that updates follow source cadence. It does not contradict annotations and provides useful context on data composition and freshness beyond structured fields.

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?

The description is two concise sentences: the first front-loads the return value and composition, the second gives clear use-case guidance. 'Updates: on source cadence' is a compact, useful addition. Every sentence earns its place with no redundancy.

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?

The description explains output fields, use cases, and update cadence, but it does not clarify how the target county is specified. The input schema has no required parameters, so an agent may not know how to select a county, leaving a significant completeness gap for an otherwise well-described tool.

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% for the sole optional 'days' parameter, so the schema fully documents parameter semantics. The description adds no additional parameter context, which aligns with the baseline 3 for high schema coverage.

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 clearly states the tool returns a 0-100 county convenience score, a composite of three specific layers joined on county_fips, with named output fields. This specific verb-resource pair ('Returns a score') distinguishes it from the vast sibling list and makes its purpose unmistakable.

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?

Explicit 'Call when...' scenarios are given covering a range of user intents (comparing places to live, relocation, site-selection, etc.). However, it does not mention alternatives or when not to use the tool, so it stops short of a 5.

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