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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds real context beyond that: a 30-day cache, geographic scope limited to three WA counties, and provenance rules (which facts carry a source citation and which do not). The offLotFt/screen:true caveats are genuinely useful disambiguation, though they edge into explaining return values that the output schema already covers.

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 verb, resource, and scope, and the closing routing sentence is well placed. The mid-section caveat about offLotFt/screen:true is compressed into a run-on that takes a careful read to parse, which costs a point.

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?

An output schema exists and annotations are rich, so the description needn't cover return shape, and its coverage of scope, provenance, and sequencing is strong. It is silent on failure modes — what happens for an address outside King/Pierce/Snohomish or an unlocatable parcel — which is the one thing an agent would still have to discover by calling.

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 both parameters are fully documented in the schema itself, including the 3–250 char bound, county constraint, and the cache-bypass behavior. The description adds no parameter-level detail (no address format guidance, no discussion of when forceRefresh is worth the cost), so it matches the baseline for schema-does-the-work tools.

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 verb chain (geocode → resolve parcel) and an explicit return set: zoning, setbacks, overlays, lot area, jurisdiction routing, prior-permit history. It also names the downstream siblings it feeds (check_permit_requirements / estimate_permit_fee), so an agent can place it in the workflow without opening the schema.

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 a concrete triggering utterance ("what can be built at 123 Main St Seattle?") and a sequencing rule relative to two named siblings. No explicit when-not-to-use case or handling for out-of-area addresses, which keeps it short of a 5.

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