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

Annotations already indicate the tool is read-only and idempotent. The description adds context beyond annotations by explaining that the result sums assets across all brokers and returns only value and date. No contradictions with annotations.

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 extremely concise: two sentences that front-load the core purpose and return format. Every word adds value, with no redundancy or unnecessary detail.

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 simplicity of the tool (two optional parameters, no output schema), the description covers the main operation and return format. However, it omits parameter details, leaving ambiguity about the 'account' parameter and date format. It is minimally viable but incomplete for an agent to use without additional knowledge.

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 input schema has two parameters (data, account) with zero description coverage. The description only hints at the 'data' parameter by mentioning 'numa data', but does not explain its format or the purpose of 'account'. With 0% schema coverage, the description should compensate but fails to provide adequate parameter semantics.

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 clearly states the tool retrieves total consolidated assets on B3 (sum of all brokers) on a date, and specifies the return format as {valor, data}. This is a specific verb-resource pair, and the description distinguishes it from siblings like b3_get_carteira (portfolio) or b3_get_posicao (position) by focusing on consolidated assets.

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?

No guidance is provided on when to use this tool versus alternatives, nor are there any prerequisites or exclusions mentioned. The description only states what it does, not when it is appropriate.

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