list_investments

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

Annotations provide readOnlyHint=true, so the description doesn't need to restate safety. It adds useful behavioral context by naming the data source (Open Finance Brasil Fase 4) and the returned fields (gross amount, net amount, contracted rate, indexer). It stops short of disclosing consent/auth prerequisites, but the read-only behavior is well covered.

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 front-loaded with a clear purpose, then structured into concise Args and Returns sections. Every sentence adds value, and it avoids redundantly restating the schema enum values.

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 output schema covers return values, and annotations cover safety, so the description focuses on purpose and parameters effectively. However, it omits the critical prerequisite of establishing an Open Finance consent before listing investments, which is likely necessary given the sibling consent-management tools. It also doesn't clarify that ctx is framework-injected, not a user param.

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 descriptions are missing (0% coverage), and the description compensates by defining subject_id as the user's CPF and bank as a participating bank. The bank enum is self-documenting. The mention of ctx is somewhat confusing because ctx is not in the schema, but it clarifies that it provides access to shared adapters rather than being a user-supplied parameter.

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 opens with a specific verb and resource: 'Lists a user's bank fixed-income investments' and enumerates exact product types (CDB, LCI, LCA, RDB). This clearly distinguishes it from sibling tools like list_funds, list_variable_incomes, and list_treasure_titles.

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 fixed-income framing and product enumeration make it clear when to use this tool versus sibling asset-class listing tools. However, it does not explicitly mention that an Open Finance consent must be established first (via sibling consent tools), so exclusionary guidance is incomplete.

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