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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered; the description adds genuinely new behavior beyond that — word-boundary matching, abbreviation normalization ('Street'='St', 'Northwest'='N.W.'='NW'), suite/unit/'#' stripping, and what a miss returns (coverage). It does not describe result ordering or how coverage output is shaped, which keeps it off a 5.

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?

Front-loaded with the core action, then the matching rules that materially affect how an agent should format input. It is dense but nearly every clause carries operative information; the parenthetical definition of FactLot Registry is the only mildly expendable part.

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?

For a two-parameter search tool with full schema coverage, rich annotations and no output schema, this covers what an agent needs: accepted input forms, rejected input forms, normalization behavior, and failure semantics. Nothing required to call it correctly is missing.

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 schema documents both parameters and a 3 is the floor. The description still adds real semantics for 'query' — the comma is meaningful (everything before the first comma is the street line), normalization rules apply, and city-only or partial-word input silently matches nothing — going beyond the schema's brief field description.

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?

Opens with a specific verb and resource: 'Find commercial parcels by situs address.' The scope word 'commercial' plus 'situs address' implicitly separates it from entity lookup or generic search, but the description never names the sibling tools (registry_search_entities, id_parcel, search) it should be preferred over, so differentiation is left to inference.

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?

Gives concrete positive and negative usage guidance: supply a house number or a street name with its type, and 'a city or a part of a word alone matches nothing.' It also states that a no-match response returns coverage rather than an error. It stops short of naming alternative tools for entity or parcel-ID lookups, so routing guidance is clear but not complete.

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