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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. Beyond that, the description discloses the returned payload in detail and adds a genuine caveat — deed references and links appear only 'where the county provides them' — signalling variable data coverage that the agent would otherwise not expect.

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?

A single front-loaded sentence leads with the scope before enumerating contents, and every clause conveys distinct information. The parenthetical listing of ownership-record attributes is dense but earns its place as return-value detail in the absence of an output schema.

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 carries the burden of describing return values and does so thoroughly. Remaining gaps are minor: it doesn't mention the include_geometry option or what happens when a parcel cannot be found.

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 the alternative-lookup logic: pin alone suffices, while apn requires county to disambiguate. That relationship between parameters is meaningful even though the schema partially hints at it in the county field.

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 resource and scope: 'Everything known about one parcel', enumerating the parcel record, ownership history, sale history, and Register of Deeds link. This clearly separates it from list/search siblings like search_properties, though it doesn't name a sibling explicitly.

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?

It gives the lookup modes ('by pin, or by apn plus county') which is useful invocation guidance, but never states when to prefer this over search_properties, property_at, or owner_portfolio. Usage is implied by 'one parcel' rather than stated.

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