Sum property value in an area

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

With no annotations available, the description carries the full behavioral disclosure burden. It adds meaningful traits beyond the schema: null valuations are treated as 0, the result includes a count, and the tool reads from a per-county property query table with a fallback to a derived geo index. It does not detail error behavior or output type, but the core behavioral expectations are covered.

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 senences with no filler, front-loading the core return value and geometry contract. The null-handling and data-source notes are useful and compactly stated.

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?

Given no output schema, the description adequately states what is returned: the sum and the in-area count. It also covers key input constraints, null behavior, and fallback behavior. It does not mention edge cases such as empty result sets or invalid polygons, but the core information needed for correct invocation is present.

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 coverage is 100%, so the baseline is 3, but the description adds non-obvious parameter semantics: exactly one of bbox or polygon must be used, and the geometry filter is based on centroid fallback rather than arbitrary overlap. It also clarifies that the county parameter may be inferred in single-county deployments.

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 states a specific verb and resource: it returns the exact sum of avm_value over properties whose centroid falls inside a user-supplied bounding box or polygon, plus the in-area count. This clearly separates it from sibling tools like findPropertiesInArea or queryProperties, which are oriented toward finding or listing properties rather than aggregating values.

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 explicitly instructs the agent to provide exactly one of bbox or polygon, which is essential for correct use. It also clarifies the centroid-containment rule and the read path. It does not explicitly name alternatives or state when not to use this tool, but the aggregation purpose makes the intended context reasonably clear.

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