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

Annotations cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description only needs to add what they cannot. It does: it discloses the return payload (place_id keyed as {state_fips}-{county_fips}, net flows in returns/people/AGI, top origin/destination counties), the data vintage (FY2022-2023), and the privacy posture (aggregate IRS statistic, zero PII). Only pagination/ordering behavior is left unstated.

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, front-loaded with the action and resource, then the identifier format, then provenance/privacy. No filler and nothing repeated from the schema beyond what is needed for orientation.

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 carries the return-value burden and does so by explaining place_id, the metric families, and the vintage. It is nearly complete for a two-parameter search; the only gap is ordering/pagination semantics for limit.

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 both q and limit are already documented, and the baseline is 3. The description reinforces that q accepts county or state names but adds no syntax, matching rules, or limit behavior beyond the schema.

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 (search) plus the precise resource (IRS county-to-county migration flows) and the lookup key (county/state name). It also names the data vintage and provenance, so an agent can distinguish this from the many other *_search tools without opening the 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?

Usage is implied rather than stated: the mention of returning a place_id 'to pull a county's net migration and top origin/destination counties' hints at a two-step pattern, but there are no explicit when-to-use/when-not conditions or named alternatives. A sibling such as ag_census_county_search or income_by_zip_search is never contrasted.

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