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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds behavioral context by specifying the data source, the counting modes (consecutive vs. total weeks), and the return content (FIPS codes, state, week counts). It does not mention rate limits or pagination, but the annotations cover the main behavioral concerns.

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, information-dense paragraph that front-loads the core function and data source, then lists filters and use cases. It is slightly longer than necessary—the use-case list could be trimmed—but every sentence adds value and there is no redundancy.

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?

The description covers the tool's purpose, filters, data source, and return fields, and the output schema exists to document return values. It does not mention the 1-year maximum range constraint (which is in the schema) or any pagination/limit behavior, but for a read-only query tool with a rich schema and annotations, the description is sufficiently complete.

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 six parameters thoroughly. The description adds a high-level summary of the filters (state, drought level, minimum weeks threshold, consecutive vs. total) but does not add new details beyond the schema. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 uses a specific verb ('Find') with a clear resource ('US counties that experienced at least N weeks of drought at or above a specified drought severity level during a given time period'), names the data source (USDA/NOAA US Drought Monitor), and lists the key filters. It distinguishes itself from sibling drought tools like drought.county.stats and drought.national.stats by focusing on county-level week counts with threshold and time-period filters.

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 states the tool is 'Useful for identifying persistent drought-affected regions, prioritizing disaster relief, analyzing multi-year drought patterns, and supporting agricultural or water resource planning,' which gives clear context for when to use it. It does not explicitly name alternative tools or state when not to use it, but the use cases and the filter options make the intended usage clear.

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