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

Annotations already declare the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint), so the bar is lower. The description adds useful context beyond them: the authoritative source (CDC NWSS), the metric definition (WVAL), and the population-weighted methodology, which helps the agent interpret results. It omits freshness/caching and rate-limit behavior, so it is not fully complete.

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?

One tight sentence plus one inline example, with the resource and scope front-loaded. Nothing is padded, and the example disambiguates argument shape immediately.

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?

There is no output schema, so the description carries some burden of explaining the return, and 'trend' plus 'trailing weeks of history' gesture at a time series without giving its shape or units. For a simple three-parameter read tool with fully documented inputs and clear annotations, this is nearly complete but leaves the returned structure ambiguous.

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 state, weeks, and pathogen including aliases and defaults. The description restates the state/pathogen call in an example but adds no semantics (e.g., week granularity, WVAL scale) beyond what the schema provides, so the baseline of 3 applies.

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?

It names a specific metric (CDC NWSS wastewater viral activity level, WVAL), a specific scope (one US state or territory), and explicitly positions itself against the sibling wastewater_national_trend by describing itself as the state-scoped version of the same methodology. An agent can distinguish it from the national tool without opening either schema.

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 establishes context — retrieve state-level WVAL, using the same methodology as wastewater_national_trend but scoped to in-state reporting sites — which implicitly routes the agent to the right sibling. However, it never states an explicit when-to-use rule or a when-not-to-use condition, so it stops short of the full routing guidance a 5 would require.

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