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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context beyond that: the dataset is frozen historical, auth is not required, the license is CC BY 4.0, and the temporal coverage is limited. No contradiction with annotations exists.

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 compact and front-loaded: it states the action, data source, filters, temporal scope, and licensing in four sentences with no filler. Every sentence earns its place.

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 is complete for a read-only, filtered historical query tool: it covers source, scope, coverage, licensing, and auth. The output schema supplies return-value details, and annotations cover safety. A small gap is the lack of explicit guidance on which sibling tool to choose for live or other ECDC datasets.

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 fully documents all four parameters. The description adds only a brief restatement of filtering by country, indicator, and ISO week, which minimally enhances the schema. This matches the baseline for high schema coverage.

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 states a specific verb and resource: 'Get historical weekly COVID-19 case and death counts by country from ECDC...' This clearly distinguishes it from sibling tools like ecdc-surveillance.covid.hospital_icu and testing_rate, which cover different metrics. The ECDC data source and cases/deaths scope make the tool's purpose unambiguous.

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 useful context: it covers only 2020-W01 through 2023-W47 and is a frozen historical dataset, not live surveillance. However, it never explicitly names alternatives or gives when-not-to-use guidance, so an agent must infer from sibling names that other tools may be better for live or non-case/death data.

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