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

Annotations already establish readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds genuine context beyond that: what the call surfaces (plan, credits, rate limits, tool inventory) and that it is a diagnostic/introspective call rather than an operative one.

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 sentences, both earning their place: the first defines the output, the second defines when it is warranted. The usage constraint is front-loaded and there is no filler.

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 zero parameters, a rich output schema, and annotations covering the safety profile, the description need not explain return shape. It supplies exactly the missing piece — when this diagnostic tool is appropriate — making the definition complete for calling it correctly.

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 no parameter semantics are required; the baseline for a no-parameter tool applies. Nothing in the description misrepresents or omits an input.

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 a specific verb and resource — identify the account, user, and credential behind the connection — and enumerates returned context (plan, credit balance, rate limits, available tools). Sibling differentiation is only implied via 'other tools already act on this account' rather than naming a specific alternative, so it stops short of a 5.

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 states both when to use it (troubleshoot the connection, check credits and limits) and when not to use it (other tools already act on this account). The condition selecting this tool versus the action-oriented siblings is explicit and leaves nothing to inference.

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