county_history

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

Annotations already declare readOnlyHint=true and openWorldHint=true, but the description adds real behavioral context: the shape of each returned version (dates, event string, statute) and the non-obvious atlas convention of filing counties under their modern state. It does not cover caching/rate-limit behavior beyond the schema's refresh note.

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 purpose, then a concrete example of a returned event, then the sibling routing rule. Sentences are short and each earns its place, though the telegraphic fragment style ('Each version carries its dates, the event..., and the statute.') borders on clipped.

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-shape burden and discharges it by naming the per-version contents (dates, event, statute). For a single-county lookup, pagination is unlikely to matter, so nothing critical 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 all three parameters are already documented, including the modern-state convention for 'state' with its own WV example. The description reinforces that convention but adds no syntax, format, or edge-case detail the schema lacks; 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 precise verb+resource: returns every version of one county over time, with creation date, parent source, and each subsequent change, plus the statute citation. It explicitly contrasts itself with the sibling county_at, so an agent can pick correctly without inspecting either 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?

Names the alternative (county_at) and the exact condition that selects it: use county_at for 'a particular place,' because a county's history does not record which version held a given farm. This is an explicit when-to-use-this vs when-to-use-that statement.

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