list_categories

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

With no annotations, the description carries the full behavioral burden. It usefully discloses return content: grouping by bucket, an active flag, and the monthly reference value when present. However, it never states this is a read-only, side-effect-free call, nor anything about permissions or result size, leaving the safety profile to be inferred from the name.

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?

Three sentences, front-loaded with the resource and grouping, then the returned fields, then the cross-tool usage note. No filler, though the bucket enumeration is dense and could be trimmed.

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?

There is no output schema and no parameters, so the description must explain what is returned, which it does (bucket grouping, active status, monthly reference value). Given the tool's simplicity, an agent has enough to call it and use its output correctly.

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 nothing to document and the baseline is 4. The description does not need to compensate for any schema gap.

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 (list) and resource (categories), and adds scope detail: categories grouped by bucket type with the enumerated buckets (rendimento, despesas fixas, orçamento, extras, poupança). This distinguishes it from siblings like list_movements and list_accounts without ambiguity.

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?

Explicitly routes the agent to a sibling: 'Use os nomes daqui no filtro de list_movements', telling it where the category names are consumed. It gives clear context for use but states no when-not or alternatives to list_categories itself, so it stops short of full 5-level guidance.

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