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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the weekly publication cadence, the Tuesday-valid/Thursday-release lag, and the fact that categories are cumulative (D1+ = D1-D4).

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?

Content is front-loaded with what the tool returns before the invocation details, and there is little waste. Slightly dense with several clauses packed together, but every sentence carries information.

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 by explaining what is returned (categories None/D0-D4 and cumulative semantics) and the two measure options. Date-range behavior is also covered, so an agent has what it needs to call it 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?

Schema description coverage is 100%, so every parameter is already documented in the schema. The description restates the matching modes and default measure ('area') and adds the cumulative-category note, but adds little syntax or meaning beyond the schema. Baseline 3 is appropriate.

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+resource ('Weekly U.S. Drought Monitor drought-severity statistics for one U.S. county') and spells out what is measured (percent area or population, categories None through D4). The county scope is unambiguous, which implicitly separates it from us_drought_state and us_drought_national, though those siblings are never named.

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 concrete invocation guidance: match by state+county or FIPS, and omit dates for the latest map. What is missing is any explicit when-to-use-this-vs-alternative routing to us_drought_national/us_drought_state.

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