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

Annotations already declare readOnlyHint=true and destructiveHint=false, so a 3 is appropriate. The description adds filtering capability but does not disclose pagination behavior or other side effects. It is consistent with annotations and adds minor value.

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 uses two efficient sentences, front-loaded with the main purpose. No redundant information; every word serves a purpose.

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 tool with 2 parameters and a output schema, the description covers the core functionality and filtering. It could mention pagination (implied by limit) or ordering, but overall is sufficient given the annotations and schema.

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 coverage is 100% for both parameters (limit and status). The description adds meaning to the status parameter by suggesting usage for active, cancelled, or past-due subscriptions, but it misses the 'trialing' option. Baseline 3 holds because the schema already well-documents the parameters.

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 subscriptions and can filter by status. It distinguishes from siblings like get_subscription (single) and cancel_subscription (mutation). However, it omits one enum value ('trialing') from the list of example filters, slightly reducing completeness.

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?

No explicit guidance on when to use this tool vs alternatives such as get_subscription (to retrieve a single subscription) or other subscription management tools. The description does not provide when-to-use or when-not-to-use context.

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