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

With no annotations, the description carries the full burden and does so well: it discloses the accounting quirk that assets == liabilities_and_equity, that net_result folds into liabilities_and_equity, and that equity is empty unless the opening batch is present. It also notes the fiscal_year_cut behavior (stamped fiscal_year_id, not posting date). Missing only permissions/cost/volume behavior, which is minor for a read report.

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 core purpose is front-loaded and each subsequent sentence adds a distinct caveat rather than restating. It is dense and slightly cluttered by ticket references (ZET-155, ZET-166) and parentheticals, but the length is justified by the accounting subtleties being disclosed.

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 report tool with no annotations and no output schema, the description supplies the semantic frame an agent needs (position vs movements, equity/net_result folding, year cut basis). It stops short of naming the returned fields or shape, which is the one gap given the absence of an output schema.

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%, so the description must compensate, and it does for the two non-obvious parameters: fiscal_year defaults to the latest posted year with no all-years mode, and period_id turns the result into a movements aggregate. company_id is left undocumented, but its meaning is self-evident from the context.

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 states a concrete output (assets vs liabilities + equity) for a specific scope (one fiscal year) with a stated convention (signed by natural side). It does not explicitly distinguish itself from close siblings like gl_profit_and_loss or gl_trial_balance, only borrowing trial-balance window rules, so it stops short of a 5.

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?

It gives meaningful context - default fiscal_year is the latest posted year, there is no all-years mode, and passing period_id switches to a movements aggregate rather than a position. However it never states when to choose this tool over gl_profit_and_loss or get_financial_statements, so guidance is implied rather than explicit.

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