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

Without annotations, the description carries the behavioral burden well: it discloses plan limits (100 images/month, watermark), that the API key is shown only once, and that it must be added to the server's Authorization header. It omits duplicate-email/idempotency behavior and error handling, so it is not fully complete.

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?

Two compact sentences, front-loaded with the action and plan limits; the one-time key instruction is critical and earns its place. No 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 single-parameter account-creation tool with no annotations or output schema, the description covers plan constraints, return value, and the critical auth-header next step. It leaves gaps around duplicate accounts and email semantics, but is close to complete.

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 schema has one required parameter with 0% description coverage, so the description must explain it. It never mentions email—e.g., whether it is the login identifier, must be unique, or triggers verification—so it adds no meaning beyond the schema's type.

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 action (create) and resource (Platemark account), and adds the account tier and return value (API key). An agent can distinguish it from account_status, which checks status rather than creating an account.

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?

Implies use when a user lacks an account but does not explicitly state when to use it versus account_status or what to do for an existing account. No exclusions or prerequisite guidance beyond the free plan details.

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