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

Annotations already declare readOnly/idempotent/non-destructive, so the description's job is to add context — and it does, disclosing the breadth of the returned record and flagging that some checks are Colorado-specific. It stops short of saying what happens on no-match or multiple-match, but against annotation coverage this is solid.

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 purpose, then a dense but purposeful enumeration of returned fields and lookup modes. The field list is long but each item signals a distinct checkable attribute, so little is wasted; a two-sentence split would improve scanability.

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 content and does so thoroughly, including jurisdiction caveats. The remaining gap is failure/ambiguity behavior and whether results differ when looked up by coordinates versus address.

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% and each parameter already documents its own format, so the baseline applies. The description adds only modest value: the pairing hints (lat with lng, zip with address) and the note that the key comes from an earlier answer.

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 precise statement of the resource and scope: 'One parcel's stored record and its checks', then enumerates exactly what is returned (county value, last sale, years held, lot, zoning, water, outbuildings, sellable signs, plus Colorado checks). The singular 'one parcel' implicitly contrasts with the plural sibling find_parcels, so an agent can tell which to reach for.

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 final sentence gives three lookup routes and a conditional hint ('with ZIP when you have it', key 'from an earlier answer'), which is useful invocation guidance. However, it never states when to use this tool instead of find_parcels or run_signal, nor what to do if the address is ambiguous.

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