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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety needs no restating. The description earns credit for a non-obvious behavioral disclosure beyond annotations: it explicitly excludes payment-card data from the response, bounding what the agent can expect. It does not say what is returned when no subscription exists (e.g., trial-expired vs. unknown), which keeps it out of 5 territory.

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?

A single front-loaded sentence with no filler: the returned resource is stated first and the negative guarantee (no card data) is appended. Nothing is wasted and nothing important is buried.

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?

The tool is simple (no parameters, read-only), an output schema exists to describe return values, and annotations cover the safety profile, so the description does not need to explain result shape. The one remaining gap is the absence of any auth or scope prerequisite, which matters for an entitlement lookup tied to an account.

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 takes zero parameters, so there is no parameter meaning for the description to add; the baseline of 4 applies. Nothing in the description conflicts with the empty schema.

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 a specific verb and resource ('Returns subscription and trial entitlement status'), which is clearly distinct from the financial-report siblings like get_business_report or get_job_financials. It stops short of naming a boundary or alternative, but the resource is unambiguous.

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?

Usage is only implied: an agent can infer this is the call for checking subscription/trial entitlements before gating a paid action. There is no explicit 'use when' statement, no mention of prerequisites (e.g., authentication context or an org/tenant selector), and no stated alternative.

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