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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds that quotes are 'atualizadas' and for assets tracked by Meelion, but does not disclose behavior like refresh rates, data source, or response format. This is a modest addition but not a comprehensive disclosure.

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 three sentences, each serving a clear purpose: stating the function, providing usage guidance, and listing English keywords for matching. It is front-loaded with the main purpose and contains no redundant information.

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?

The tool is simple with one optional parameter, no output schema, clear annotations, and a concise description. The description provides enough context for selection and invocation, though it does not describe the return format, which is a minor gap given the tool's simplicity.

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 optional 'assets' parameter is already well-documented. The description adds natural language mapping (dollar, euro, etc.) but does not introduce new syntax or constraints beyond the schema, so the baseline score of 3 is appropriate.

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's function: returning updated quotes for assets and currencies tracked by Meelion, with specific examples like dollar, euro, gold, silver, and Bitcoin. This distinguishes it from sibling tools focused on investments, indicators, and projections.

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 explicitly says when to use the tool ('Use quando o usuário perguntar sobre câmbio, cotação atual, variação de moedas, metais ou criptoativos...'), providing clear context. It does not mention when-not to use it or name alternatives, so it misses the top score.

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