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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool returns entities with borders on the map and optionally filters by region, but it does not specify the output format (e.g., list of names, IDs), whether the operation is read-only (though implied), or any edge cases like handling years with no matches. The description is transparent about the core behavior but lacks detail on output and potential limitations.

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 description is a single, well-structured sentence that front-loads the primary action and resource, followed by the optional filter. There is no redundant information or filler, and every word contributes to understanding the tool's purpose. It is appropriately sized for the tool's simplicity.

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?

Given the tool has only two parameters, no output schema, and no annotations, the description is reasonably complete. It clearly explains what the tool does and the optional bbox filter. However, it could be improved by stating the expected return format (e.g., a list of names) or clarifying what 'borders are on the map' means precisely, especially for edge cases like incomplete historical data. These are minor gaps, and the description suffices for an agent to call the tool correctly.

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?

The input schema already documents both parameters with 100% coverage: year (with BC notation and no year 0) and bbox (bounding box coordinates). The description adds minimal semantic value, merely echoing 'in a given year' and 'overlapping a region,' which essentially restates the schema. Since the schema already covers the parameters, the description does not need to add much, but it also does not provide any additional clarifications beyond what is already known.

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 description clearly states the tool lists states, empires, and cultures on the map for a given year, with an optional region filter. The verb 'List' and the resource 'states, empires and cultures' are specific, and the OpenHistoricalMap data source adds context. It is distinct from siblings like find_polity (which finds a specific polity) and search_events (which searches events), so an agent can differentiate it without further investigation.

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?

The description provides no guidance on when to use this tool versus its siblings (find_polity, search_events). It does not mention alternatives or when not to use it. The purpose implies usage for listing historical entities at a specific year, but there is no explicit context or exclusion criteria, leaving the agent to infer when this tool is appropriate.

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