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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so 'Reading changes nothing' merely restates structured data. The description does add some value by flagging that the account may carry a scheduled deletion date and can change over time, plus which identity the response reflects (API key vs connected app).

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 front-loaded with the highest-value information: what is returned first, then why to call it. No filler or repetition beyond the brief safety closing.

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?

An output schema exists, so return-value detail is out of scope, and a zero-parameter tool needs no argument guidance. The description covers identity context, payload contents, and the reason to poll it, leaving nothing an agent needs missing.

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 the description carries no parameter burden and the baseline applies. Nothing about invocation arguments needs explaining.

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 ('Get the account this API key or connected app acts on') and enumerates the payload (id, role, plan, scheduled deletion date). That scope cleanly separates it from siblings such as get_plan_usage or get_payment_record, which cover narrower slices.

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?

'Check it to notice when that account changes or is ending' gives a clear motivating context for calling it. It stops short of naming an alternative tool or stating when not to call it, so it falls just below the top band.

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