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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds only that the payload contains endpoints and usage — useful but thin; it says nothing about error behavior when an instance_id is unknown or whether the result can be stale.

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 short sentence with no waste and the key noun front-loaded. It is efficient, though it is arguably too terse rather than optimally structured.

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 must hint at return contents, and 'its endpoints and usage' is a minimal but real indication. For a low-complexity two-parameter read tool with full schema coverage and clear annotations, this is adequate though sparse.

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?

Schema description coverage is 100%, including provenance for instance_id and the conditional/alternate auth note for passport_token. The description adds no parameter meaning beyond the schema, so the baseline of 3 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 states the resource (a single utility) and what it returns (endpoints and usage), and the singular 'one' implicitly distinguishes it from list_utilities. However, there is no explicit verb like 'fetch' or 'retrieve' and no direct reference to the sibling, so differentiation relies on inference.

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 description gives no when-to-use guidance, no prerequisites, and never names list_utilities as the alternative for browsing. The only routing hint lives in the instance_id schema description ('from buy or list_utilities'), not in the tool description itself.

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