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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, but the description adds no behavioral context at all: no rate limits, no indication of result size, no mention of whether the list is stable or API-specific.

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 sentence with no padding, and the purpose is front-loaded. Minor redundancy/awkwardness in 'you will find obtain' costs a point.

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?

For a zero-parameter lookup with an output schema present, the description need not explain return values. It correctly ties the result to the date fields it feeds, leaving only minor gaps about calling frequency.

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?

Zero parameters, so baseline 4 applies; there is nothing for the description to clarify beyond the schema.

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?

States a specific verb and resource: returns the list of dates usable in the first_date/second_date fields of the Domain Metrics by Categories endpoint. This distinguishes it from most siblings, though the wording is clunky ('you will find obtain').

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 implies when to call it by naming the consumer endpoint (Domain Metrics by Categories), but gives no explicit when-to-use/when-not guidance and names no alternative among the many sibling tools for the same purpose.

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