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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds minimal behavioral context beyond the schema, such as the ability to filter by status. With annotations present, the bar is lower, and this description meets it without adding rich behavioral details like response format or pagination.

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 one sentence that leads with the primary action ('List member subscriptions') and follows with an optional filter use case. It is concise, front-loaded, and every word contributes to understanding the tool's purpose and typical usage.

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?

This is a simple list tool with only two optional parameters, an output schema present, and strong annotations (readOnly, idempotent, non-destructive). The description, combined with the schema and annotations, provides complete context for what the tool does and how to use it. No significant information is 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 input schema has 100% description coverage for both parameters (limit and status), so the baseline is 3. The description reinforces the status parameter by mentioning filtering by active/cancelled/past-due, but it does not add meaning beyond what the schema already provides. It meets the baseline without going above.

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 clearly states the tool lists member subscriptions, using the specific verb 'list' and the resource 'subscriptions'. It distinguishes from sibling tools like get_subscription (singular fetch), create_subscription, cancel_subscription, etc., by implying a collection listing operation.

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 provides clear context: use this to list subscriptions, optionally filtering by status. It does not explicitly mention alternatives or exclusions, but the 'list' vs 'get' pattern in sibling names implies the distinction. This is slightly above implied usage, as it gives a concrete filtering use case.

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