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

Annotations already cover read-only, idempotent, non-destructive, open-world. The description adds genuinely useful context beyond them: results are bounded and paginated, include LIC/non-LIC and county counts plus source evidence, and are scoped strictly to the 2018 cycle corpus.

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 question the tool answers, then layers in return shape, filters, and caveats. Dense but each sentence carries distinct information; slightly longer than strictly necessary but no filler.

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?

No output schema exists, so the description carries the burden of explaining returns (bounded paginated aggregate groups with LIC/non-LIC and county counts plus source evidence), which it does. Filters and scope limitations are covered; only pagination defaults are left to the schema.

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 all six parameters (limit, offset, group_by, tract_type, jurisdiction, response_format) are already documented in the schema. The description references the grouping dimensions and optional jurisdiction/tract_type filters but adds no format or syntax detail beyond what the schema provides.

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 (summarize) and resource (final 2018-cycle QOZ designations) and enumerates the exact aggregation dimensions (overall, jurisdiction, county, tract type, ACS eligibility source). The aggregate nature clearly separates it from sibling lookup/search designation tools without opening any 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?

"Use for coverage and market-screening summaries" gives clear context, and it adds two important exclusions: counts are not a measure of investment attractiveness and do not cover 2026-2027 redesignation tracts. It does not, however, name a specific sibling (e.g. search_designations) as the alternative for non-aggregate needs.

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