zip_crosswalk

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

No annotations present, so description carries full burden. Describes the return format (geography + res_ratio) and hints at selection behavior (highest-share county). Does not mention potential edge cases (missing ZIP, multiple matches) but overall informative.

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?

Two sentences with no extraneous text. Front-loaded with core purpose and immediately useful detail (res_ratio, entityid resolution).

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?

Given no output schema, description explains exactly what is returned and how to interpret it (res_ratio, highest-share county). Includes cross-references to sibling tools for follow-up. Complete for a simple geospatial mapping tool.

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 baseline is 3. Description adds no additional meaning to parameters themselves, but provides context on the output (res_ratio) that could influence parameter choice.

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?

Explicitly states the mapping from 5-digit ZIP to county/tract/CBSA/CD using HUD-USPS crosswalk, and mentions the res_ratio return value. Distinguishes from sibling tools like list_counties by referencing it as a subsequent step.

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?

Clearly describes the use case: mapping ZIPs to geography. Provides guidance on next step (resolving highest-share county via list_counties). Lacks explicit when-not-to-use or alternatives, but context is sufficient.

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