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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description's 'Read' is consistent with those. It adds valuable behavioral detail: the access_token is short-lived and listing-bound, warning the agent about token expiration and scope. It also lists the returned analytics categories, giving a sense of the response content without redundancy.

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 entire description is one front-loaded sentence that leads with the verb and resource. No filler or repetition; every element 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 tool has five parameters and an output schema, which covers return values. The description covers the core resource and auth constraint, but lacks guidance on where to obtain the short-lived token and on the date-range/granularity behavior. These gaps leave an agent with questions before calling the tool.

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?

With zero property descriptions in the schema, the description is the only source of meaning for parameters. It clarifies listing_id ('one listing's') and access_token ('short-lived listing-bound token'), which are the two required fields. However, it does not explain the semantics of from, to, or granularity beyond what the schema's types and enum already provide, so compensation is incomplete.

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 ('Read') and precise resource ('one listing's aggregate funnel, spend, rank history, freshness and time series'), making the tool's function immediately clear. The detailed data categories distinguish it from sibling analytics tools, even without naming alternatives. The token requirement adds context without muddying the purpose.

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 conveys the context in which the tool is used: fetching single-listing analytics with a listing-bound token. It implicitly rules out multi-listing or comparison use cases, which are handled by sibling tools like compare_resources. However, it doesn't explicitly state alternatives or conditions for choosing this tool, so it stops short of a 5.

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