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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds that every account is returned with opening, movement and closing balances, which is genuinely useful behavioral detail in the absence of an output schema, but it says nothing about volume, aggregation level, or whether it is paginated.

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?

Two short sentences, front-loaded with the content summary. The trailing "GET /trial_balance." is an endpoint restatement that adds little for an agent, but the overall text is far from bloated.

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?

With three optional parameters and no output schema, the definition covers the basics — the report's content and its period scoping. It leaves open how large the result set is and how it behaves with default (today) dates, gaps an agent may need to discover at call time.

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% and the enum parameter is fully documented in the schema, so the description only needs to not contradict it. "For a period" adds no syntax, default behavior, or precedence rules beyond what start_date, end_date, and compare_type already state.

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?

"Trial balance for a period" names a specific resource and scope, and the clause about opening/movement/closing balances clarifies what the report contains. It does not, however, distinguish itself from adjacent financial reports such as jurnal_get_balance_sheet or jurnal_get_general_ledger, so an agent must infer which report to pick.

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?

There is no guidance on when to use this tool versus alternatives — nothing says whether to reach for the trial balance instead of the balance sheet, general ledger, or profit and loss. The only contextual hint is the implicit 'for a period' framing.

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