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

No annotations are present, so the description carries the full burden of behavioral disclosure. It adds the detail that only 'active' subscriptions are returned, but it does not state that the operation is safe/read-only, mention authorization needs, or describe the return format. The verb 'show' weakly implies a non-destructive read, but this is minimal transparency.

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 a single sentence, front-loaded with the action verb, and contains no filler or redundant information. It is highly concise and well-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?

For a zero-parameter tool with no output schema, the description provides the core purpose but omits details such as the exact meaning of 'active' and the structure of the returned list. It is minimally adequate but leaves gaps that could confuse an agent expecting more context.

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 tool has zero parameters, so the baseline is 4. The description correctly does not attempt to explain parameters, and no further semantic information is needed.

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 a specific action ('show') on a specific resource ('all active subscriptions'). It distinguishes from sibling tools like subscribe/unsubscribe by being a list operation, though it does not explicitly name alternatives. The purpose is clear and not a tautology.

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 explicit guidance on when to use this tool versus alternatives. The read-only nature is implied by 'show', but no context is provided on prerequisites, exclusions, or how it fits with other subscription-related tools. This falls short of even implied usage guidance.

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