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 the output is broken down 'by account' and repeats the endpoint, which is modest extra context; it says nothing about how comparison periods behave or whether periods with no activity return empty results.

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 sentences, front-loaded with what the report is and what it contains, followed by the format constraint and endpoint. No filler.

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 no output schema, the description usefully names the returned sections (revenue, cost of sales, expenses, net profit), which is the key missing piece an agent needs. Remaining gaps (comparison columns, pagination/aggregation shape) are minor for a read-only report endpoint.

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 100%, so all three parameters including the compare_type enum are already documented in the schema. The description's only parameter-related note, 'Dates are yyyy-mm-dd', duplicates the schema, and it adds nothing about how compare_type interacts with start_date/end_date beyond what the schema states.

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?

States a specific resource (profit and loss / income statement) and enumerates the line items it returns, plus the underlying endpoint GET /profit_and_loss. An agent can distinguish it from jurnal_get_balance_sheet or jurnal_get_cash_flow by resource alone, though it never names those siblings explicitly.

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 pick this report over the balance sheet, cash flow, trial balance or executive summary, and no preconditions are stated. Usage is only implied by the word 'report' and 'for a period'.

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