Criar assinatura com link de pagamento

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

Annotations already indicate readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true. The description adds context about the hosted checkout but does not disclose side effects (e.g., whether a webhook notification is sent), authentication requirements, or rate limits. With annotations covering basic behavioral traits, the description provides adequate but minimal enrichment.

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 two sentences long and perfectly front-loaded. The first sentence states what the tool does, and the second sentence gives the primary use case. Every word serves a purpose with no redundancy or 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?

Given the tool's complexity (2 parameters, nested objects, output schema exists) and the array of sibling tools, the description adequately conveys its purpose but lacks details about prerequisites (e.g., need for a pre-existing plan), expected output behavior (though output schema exists), or constraints (e.g., rate limits). It is sufficient for a basic understanding but not fully comprehensive for an agent to select it confidently without deeper schema analysis.

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 description coverage is 100%, so the baseline is 3. The tool description does not add any additional meaning beyond the schema's property descriptions (e.g., 'items', 'settings'). Many schema descriptions are auto-generated and repetitive, but the description itself does not compensate by explaining parameter purpose or constraints. It remiss inherent from 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 explicitly states the tool creates a subscription and its payment link in one step, clearly differentiating it from siblings like create_one_step_charge (which creates a charge) and create_subscription (which likely creates a subscription without a link). The verb 'Cria' (creates) and resource 'assinatura' and 'link de pagamento' are specific and 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?

The description provides a clear use case: to allow the subscriber to complete the contract in Efí's hosted checkout. It implies when to use this tool (when a hosted checkout link is needed) but does not explicitly mention when not to use it or list alternatives. The guidance is clear but could be more comprehensive by excluding scenarios where other tools are more appropriate.

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