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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes further by stating it costs no credits, behaves identically across billing systems so no branching is needed, and that `entitled: false` with an empty list is a normal answer rather than an error. The last point is especially valuable because it prevents an agent from treating a valid negative result as a failure.

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 purpose is front-loaded in the first clause and each subsequent sentence adds usable information (output semantics, cross-billing-system invariance, empty-result normalization, credit cost, account disambiguation). It runs slightly long, with a minor redundancy in the 'so you never need to branch on that' clause, but nothing is filler.

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 one-parameter read with an output schema, the description covers everything an agent needs: when to call, how to pick the account, what the returned fields mean, and that an empty result is expected. Return-value explanation beyond the output schema is a bonus rather than a gap.

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% and the single `accountId` parameter is fully documented as a Tailwind account ID from list_accounts, so the schema carries most of the load. The description still adds operative meaning by specifying how to resolve an ambiguous account selection before calling, which is not in the 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?

The description names a specific verb and resource — check whether a Pinterest account has active, paying access — and immediately ties it to the concrete output field (`entitled`). It is clearly separable from siblings like get_account, get_account_usage, or list_accounts because it is scoped to subscription entitlement rather than account metadata or usage.

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?

It gives explicit trigger conditions (before a setup or launch flow that depends on a paid feature, or when the user asks what plan they are on) and an explicit prerequisite workflow: if the user did not specify an account and list_accounts returns more than one, ask the user rather than choosing. That is a when-to-use, a when-ambiguous rule, and a named sibling to consult.

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