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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavior beyond them: inferred ownership links carry a confidence value, and results are deduplicated per building so condominium units count once. That aggregation and confidence semantics are exactly the kind of context an agent cannot get from annotations.

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 sentences, dense but front-loaded with the resource and scope; the prerequisite is placed at the end where it belongs. Slightly compact phrasing ('inferred links carry a confidence') is efficient rather than wasteful.

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?

There is no output schema, so the description carries the burden of explaining returns, and it does describe the shape (parcels with their building plus a per-building summary). However, it omits pagination or result-size behavior and says nothing about what happens when no parcels match or when the entity URN is unknown.

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?

Only one parameter, entity_urn, and schema coverage is 100% with an example URN format documented in the schema. The description adds no extra meaning about the identifier beyond what the schema already provides, so the baseline of 3 applies.

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 resource and scope: commercial parcels currently linked to a legal entity as owner of record, plus per-building aggregation. It is clearly distinguishable from calculation siblings and from registry_search_entities, though it does not explicitly name an alternative tool.

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 prerequisite (requires a FactLot Registry) is stated, which implies the context in which the tool is callable, but there is no explicit when-to-use/when-not guidance and no sibling alternative is named for the case where the entity is unknown.

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