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

No annotations exist, so the description carries the full burden of behavioral disclosure. 'Índice' weakly implies a read-only listing, but the description does not state what it returns, whether it is safe, or how it behaves. This is minimal and mostly implicit.

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 very brief and free of fluff, which is structurally clean, but it is under-specified to the point that it is barely more than the tool's name. It is concise but not effectively informative.

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?

With no annotations, no output schema, and only this sparse noun phrase, the description is not complete enough. An agent still has to guess what the index contains, whether it returns a list of endpoints, or how it fits with the sibling tools.

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 has zero parameters, so there is no parameter semantics burden. A baseline of 4 is appropriate because there are no inputs for the description to explain.

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 'Índice da API PontoFato' essentially restates the tool name 'api_index' and adds only the product name. It provides no verb or explicit action, so an agent gets no real behavioral clarity beyond what the name already implies.

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?

There is no guidance about when this tool should be used versus alternatives. Even though the sibling list suggests api_index is likely an entry point for discovering endpoints, the description never says that or contrasts it with the other resource tools.

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