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

Annotations only declare read-only/idempotent/non-destructive. The description adds significant behavioral detail: it returns a { total:0, results:[], warning } envelope instead of throwing on 403 or upstream errors, and it performs a data-integrity cross-check that flags contradictory zeroed positions with integrity:'suspect_zeroed' and instructs agents to treat them as unavailable rather than R$0. This greatly exceeds the annotation baseline.

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 purpose and includes well-delimited sections for return behavior, data integrity, and bulk support. The data-integrity paragraph is long but necessary for a non-obvious failure mode; overall it is structured efficiently, though it could be tightened slightly without losing meaning.

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?

For a tool with no output schema, the description covers the return envelope, the per-row fields (balance, amount, dueDate, issuer, ISIN, etc.), error handling, a complex integrity warning, and bulk invocation. It is arguably complete for the tool's complexity and gives an agent all needed operational context except parameter-level semantics (captured in parameter_semantics).

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 coverage is 0% and the description only clarifies item_ids (bulk support). Params such as page, page_size, type, item, and item_id remain undocumented in both schema and description, leaving agents to guess their semantics. Schema coverage being 0% makes the description responsible for explaining all parameters, which it fails to do except for item_ids.

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 opening sentence identifies the tool as returning the investment portfolio for a connection, with a specific list of covered asset types (FIIs, stocks, ETFs, fixed income, mutual funds, retirement, COE). The verb 'Returns' and resource 'investment portfolio' clearly differentiate it from sibling tools like openfinance_list_investment_transactions and openfinance_list_transactions.

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 states the tool is for a connection with the INVESTMENTS product enabled, which is a clear prerequisite. It doesn't explicitly name alternatives or exclusions, but the resource distinction is self-evident from the portfolio focus; a 'when to use' note like 'for transactions use list_investment_transactions' would earn a 5.

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