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

Annotations already declare that this is a read-only, idempotent, non-destructive operation, so the safety profile is covered. The description adds the endpoint and the fields returned, which is useful context, but it does not discuss pagination behavior, auth needs, or rate limits beyond what the schema provides.

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 description is two compact sentences front-loading the resource and then the returned fields, with no wasted prose. Every element—scope, field list, and endpoint—adds useful information.

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 simple read-only list endpoint with rich annotations and a fully documented schema, the description is largely complete: it says what is listed, what fields appear, and the endpoint. The main remaining gap is sibling differentiation, since it does not clarify when to prefer this over the customer- or plan-specific list tools.

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%, and the single 'page' parameter is fully documented in the schema with pagination semantics and a note to pass the previous reply's next_page. The description adds no parameter-level detail, so the schema is doing all the work and baseline 3 is appropriate.

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 the specific verb and resource ('List all subscriptions') and enumerates the fields returned, so an agent knows this is a global subscription listing rather than a single-subscription getter. It does not explicitly differentiate itself from siblings like list_customer_subscriptions or list_plan_subscriptions, leaving scope distinctions partly implicit.

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?

'List all subscriptions' implies using this tool when an unfiltered list is needed, but there is no explicit when-to-use or when-not-to-use guidance. It never names the customer- or plan-scoped alternatives, so the agent must infer when this global list is preferable.

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