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

Annotations declare readOnlyHint=true and openWorldHint=true, covering safety and data freshness. The description adds the useful constraint that it avoids downloading every item, which is relevant context for performance. However, it doesn't mention rate limits, authentication, or what specific metrics are returned, leaving some behavioral gaps.

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?

A single efficient sentence that front-loads the core purpose. It earns its place by stating both the output (aggregate metrics) and a key benefit (without downloading every item). No wasted words.

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?

While an output schema exists (so return values need not be detailed), the description is incomplete for guiding parameter use and distinguishing from other dataset tools. With 0% schema coverage and no guidance on days/limit, the agent lacks critical information to invoke correctly. For a tool with two parameters and no usage guidelines, this is a significant gap.

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 coverage is 0%, so the description must compensate for two parameters (days and limit). The description hints at temporal scope with 'chart-ready' and aggregate nature, but doesn't explain what 'days' and 'limit' control. Baseline 3 is given because schema coverage is low, but the description fails to add meaning.

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 clearly states a specific verb and resource: returns aggregate metrics for the stored Chrome Web Store dataset. It distinguishes from siblings like chromewebstore_item or datasets_chrome_extensions_search by emphasizing 'aggregate' and 'without downloading every item', though the sibling names are so heavily prefixed that explicit differentiation would be stronger.

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 phrase 'chart-ready' implies a use case for visualization or trend analysis, but there is no explicit when-to-use versus alternatives like datasets_chrome_extensions_search or chromewebstore_charts. No prerequisites or exclusions are stated.

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