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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered structurally. The description adds no behavioral context such as what the AI usage payload contains, its time window, or any scope/auth requirements, contributing nothing beyond the annotations.

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?

The same endpoint string is stated twice, which is pure waste, and the remaining content is a mechanical operation ID plus a pointer sentence. It is short but not front-loaded with anything useful.

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 and an untyped parameter surface, the description would need to explain what data is returned and how to scope the query. Instead it offers only the raw route, leaving an agent unable to call this confidently against its many subscription siblings.

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 0% with two loosely typed parameters (a free-form `query` object and an empty `params` object), so the description carries the full burden. It provides no parameter names, formats, or filtering semantics, only a generic pointer to describe_operation.

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 simply repeats the endpoint path and title verbatim ('GET /api/subscription/ai-usage') without explaining what AI usage data is returned or how it differs from sibling tools like get_subscription_ai_token_cost or get_subscription_usage_summary. This is a tautological restatement of the name/title rather than a statement of purpose.

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?

There is no guidance on when to call this versus the many sibling subscription tools. The only actionable line points to describe_operation for native request schemas, which is a mechanical pointer rather than a usage condition or exclusion.

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