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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond them: complete-corpus provenance and tract-vintage/cycle warnings in the output, plus the sorted-by-total ordering. It stops short of describing pagination or error behavior, which is acceptable for a read-only analytical tool.

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-loads the core question, then layers metrics, provenance, and exclusions in three efficient sentences with no filler. Slightly dense in the metric enumeration, but every clause carries information.

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?

With no output schema, the description compensates by naming the returned counts (total, Low-Income Community, Non-LIC Contiguous, covered counties), the sort order, and the provenance/warning caveats. Nothing material an agent needs to call it correctly is missing.

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 both the jurisdictions array and the response_format enum, and the description largely restates the 2-10 selector range. It adds no syntax or format detail beyond what the schema provides, so the 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 comparison verb and resource ('Which of 2-10 requested states or territories has more final 2018-cycle QOZ designations?') and enumerates the compared metrics. An agent can distinguish it from the lookup/search/summarize siblings without opening any schema, since the cross-jurisdiction comparison framing is unique.

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 clear context (2-10 jurisdictions, 2018 cycle designations) and explicit exclusions ('not investment quality, land area, population, current eligibility, or the pending 2027 cycle'), which helpfully rules out misuse. It does not, however, name the sibling tools to use instead when a single-jurisdiction or search need arises.

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