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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds important context beyond annotations: archive nature (UDB), date range (1900–2002), and approximate geocoding precision. This is valuable behavior disclosure that annotations alone do not convey.

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 extremely concise: two sentences with no wasted words. Every sentence is front-loaded with the core action and adds a critical qualifier (date range, geocoding precision, distinction from live reports).

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 5 parameters, moderate schema coverage, and an output schema (so return values need no description), the description is adequately complete. It covers what the tool does, data scope, precision, and clarifies it's not live data. The only minor gap is not mentioning that lat is required and lon/lng are aliases, but the schema covers that.

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 60%, and the description does not repeat parameter details. The description provides high-level context (historical archive, approximate geocode) that helps interpret parameters like radius_km and lang. For the 40% of undocumented parameters, the tool's overall purpose compensates somewhat. A minor point: the description doesn't explicitly guide on the lon/lng alias choice.

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 explicitly states the tool finds historical Hatch UDB cases near a point, with specific date range (1900–2002) and approximate geocode. It clearly distinguishes itself from live Vigi-Sky reports and by context from siblings like hatch_search and hatch_stats.

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 clearly indicates the tool is for historical archive data (1900–2002) and not live reports, which helps the agent choose between this and live-report tools. However, it does not explicitly state when not to use it or name sibling alternatives, though the context signals show many related tools.

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