search_places_at_date

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

Annotations already cover safety (readOnlyHint) and scope (openWorldHint), so the bar is lower. The description still adds real value beyond them: it discloses that each result carries the jurisdiction's existence span, and that the tool 'works without credentials,' which is not captured in the annotations.

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?

The purpose is front-loaded in the first line, followed by justification and call instructions. The middle paragraph on jurisdiction instability is longer than strictly needed to invoke the tool, but it does earn its place by explaining the failure mode the tool exists to prevent.

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, and the description compensates with a short statement of what results contain (the jurisdiction's existence span). The required inputs and the auth-free mode are both covered, leaving little an agent needs that is absent.

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 all four parameters, including the year-of-record convention and within_place_id narrowing. The description reinforces the 'name as the record spells it' intent but adds no syntax or format detail beyond the schema, matching the baseline 3.

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?

The opening sentence states a specific verb and resource with a temporal qualifier: 'Resolve a place as it existed in a particular year.' That temporal-resolution framing distinguishes it from plain lookups like search_places or get_place without needing to name them.

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?

It gives clear when-to-use guidance ('Give it the name as the record spells it and the year of the record') and warns against a specific misuse (filing under the modern county). It stops short of naming an alternative sibling tool for the non-temporal case, so it falls one step below explicit routing.

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