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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, covering the safety profile. The description adds no behavioral context beyond that — no auth/permission requirements, no freshness or caching behavior, no note on latency. What it does add (the returned fields) duplicates the existing output schema, so it earns little credit.

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 front-loaded noun phrase with no filler. It is a sentence fragment rather than a complete sentence, which slightly weakens it, but every word carries information.

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 an output schema present, the description need not explain return values, and with no parameters and read-only annotations there is little else an agent requires. The only remaining gap is the absence of any usage context, which is minor for a parameterless account-info call.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies.

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 ("the connected account's plan") and enumerates the returned data points (slots used/available, size limit, features), so an agent can tell it apart from link-management siblings. The verb is implicit rather than stated, but the title plus read-only annotations make the retrieval operation 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?

Usage is implied by the content — an agent would call this when it needs account-level limits or feature availability. There is no explicit when-to-use statement, no mention of prerequisites, and no pointer to any sibling tool, so it stops short of real guidance.

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