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

Beyond the read-only/idempotent annotations, the description reveals that zoning, setbacks, and building facts carry their source, while geocode, lot geometry, and assessor records do not. It also lays out the geocode-resolve-return flow, adding meaningful behavioral context the annotations do not provide.

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?

The description is four sentences, each earning its place: purpose, pipeline/outputs, source-attribution caveat, and usage guidance. It is front-loaded with the most important fact and reads as a compact operational brief.

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 an address lookup with two well-documented parameters and an output schema, the description covers the service area, inputs, outputs, data provenance, and downstream actions. There is no obvious missing context an agent would need to invoke it correctly.

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?

The schema already fully documents both parameters, so the baseline is 3. The description adds modest value by calling it 'address-first' and specifying the county scope and use pattern, but it does not add depth to forceRefresh beyond the schema 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?

The description opens with 'Address-first parcel lookup' and then names the exact pipeline: geocoding, parcel resolution, and return of zoning, setbacks, overlays, lot area, jurisdiction routing, and prior-permit history. This clearly separates it from sibling tools like check_permit_requirements and estimate_permit_fee.

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 explicitly tells the agent when to use this tool ('what can be built at 123 Main St Seattle?') and where it sits in a workflow ('before calling check_permit_requirements / estimate_permit_fee'). This is concrete routing guidance rather than a generic statement.

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