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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered; the description adds genuine domain behavior by disclosing the vintage-matching logic and the fact that many GEOIDs are valid in both vintages. It stops short of saying what happens on a miss (no record, invalid GEOID) or what the returned record contains.

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?

Three tight sentences: what it returns, how vintages are matched, then the parameter-selection rule. No filler, and the geoid/geoid_2010/geoid_2020 decision is front-loaded where an agent will see it before opening the schema.

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?

There is no output schema, so the description is the only source for return semantics, and it says only 'Status' without indicating what fields come back (designation year, eligibility, round) or how a not-found tract is signalled. For a zero-required-parameter read tool that gap is survivable but leaves the agent guessing about the response shape.

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, and the description earns above baseline by explaining the relationship between the three parameters rather than restating them: the single geoid vs. the 2010/2020 pair, and why the pair is preferable when a property has already been geocoded. It does not state whether the pair and the single geoid can be combined or which wins if both are supplied.

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?

Names the resource precisely (an 11-digit census tract GEOID) and scopes the return to a 'status' record, which separates it from siblings like calc_90_percent_test or lookup_address. The word 'status' is only disambiguated by the title ('Opportunity Zone record'), so the description alone leaves the domain slightly implicit, and no sibling is named as a contrast.

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 concrete conditional routing: use the single geoid for a bare lookup, but 'if you already geocoded a property, pass geoid_2010 and geoid_2020 instead.' It also explains the vintage pairing rule (2010→2018, 2020→2027) that determines which input is meaningful. It does not point to alternatives such as check_qozb or lookup_coordinates for agents that have no GEOID yet.

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