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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so safety is covered. The description adds genuinely new context: the payload mirrors website FAQ wording (static, verbatim documentation) and should be fetched once, which tells the agent the content is stable and cacheable. It stops short of describing response size or structure.

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?

Two short sentences, zero filler. The content summary is front-loaded and the call instruction trails as the operative takeaway.

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?

With no output schema, the description compensates by enumerating the topics the response covers, so an agent knows what it will get back. Minor gap: no indication of payload length or whether the response is prose versus structured sections.

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 there is nothing to document; the baseline of 4 applies. The description correctly implies a no-argument call.

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 names the resource precisely: it returns explanatory content about the Zensei Index (what it is, how the score is read and built, free vs Premium tier). This clearly separates it from the sibling tools, which all return index data rather than documentation. It lacks a clean action verb, but 'about' content is 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?

'Call it once before interpreting any score' gives an explicit trigger condition and a usage constraint (once, not repeatedly). There is no explicit when-not or named alternative, but none is meaningfully needed for a static about tool.

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