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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds auth context beyond that — the key must be a utility key rather than a health owner key — which is real behavioral information an agent needs before calling. Remaining details (rate limits, what 'resume' vs 'check' means behaviorally) are absent.

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, with the capability stated first and the credential constraint second, so nothing needs to be hunted for. The compound verb 'resume/check' is slightly muddy but costs little space.

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 single-parameter read tool with annotations and an output schema, the description covers purpose and the key requirement; return values needn't be spelled out since the output schema exists. The gap is routing guidance relative to create_utility_account and set_utility_identity.

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 schema has one parameter at 0% description coverage, so the description must carry the meaning. It partially does by specifying that api_key must be a utility key and not a health owner key, which is a genuine disambiguation. It does not describe format, source, or failure behavior for an invalid key type.

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 concrete resources — stable utility identity, private coin balance and usage ledger — plus a verb ('resume/check'), so an agent knows what the tool returns. It never names or contrasts with the natural alternatives (create_utility_account, set_utility_identity), so it stops short of full sibling differentiation.

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?

The only usage signal is the credential rule ('requires a utility key, not a health owner key'), which implicitly narrows which agent/key should call it. There is no explicit statement of when to use this versus create_utility_account for first-time setup or set_utility_identity for changes, leaving the choice to inference.

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