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

Annotations already carry readOnlyHint/openWorldHint/destructiveHint, so the safety profile is covered. The description adds genuine value beyond that: it discloses the data provenance (declared by applicants, not contract prices or quotes) and that derived values are flagged computed:true, which prevents misinterpretation of the numbers.

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?

Content is front-loaded with the verb+resource and the caveat is well placed, but the entire description is duplicated in Japanese and English, roughly doubling length without adding information for a single-language reader. Each semantic sentence earns its place, but the bilingual redundancy hurts conciseness.

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 an output schema exists (so return values need no explanation), the description covers sources, coverage geography, the structure breakdown, the computed flag, and the valuation caveat. An agent has everything needed to call the tool 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?

Schema description coverage is 100%, so the schema already documents all six parameters including the enums for source and structure. The description only restates the example geo/year pair, adding little meaning beyond what the schema provides; baseline 3 applies.

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 and resource (fetch U.S. building permits) and enumerates exactly what data is returned: Census BPS buildings/units/valuation/per-unit plus city permit valuation distributions (median, quartiles, per sqft). No sibling tool deals with permits, so it is clearly distinguishable.

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?

Provides a concrete example invocation (geo='Austin, TX', year='2024') and a caveat that valuations are applicant-declared, not contract prices, which implicitly steers agents toward the pricing siblings. However, there is no explicit when-to-use/when-not-to-use statement nor any named alternative, leaving usage to inference.

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