Month Close Summary

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about the composite nature and conditional data (VAT summary if registered), which goes beyond the annotations. It does not disclose any side effects, but none are expected given the annotations. The added value justifies a 4.

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 moderately long but front-loaded with the core purpose. The first sentence defines the tool comprehensively; the second gives usage guidance. While the enumeration of components adds length, each item is meaningful and helps the agent understand the output. No wasted sentences.

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?

Given the complexity of a composite tool and the absence of an output schema, the description effectively explains what the tool returns (P&L, balance sheet, VAT summary, unreconciled transactions, outstanding invoices, overdue deadlines). It also covers the conditional VAT and usage context. Minor gaps exist (e.g., exact response structure), but for a read-only composite it is sufficiently complete.

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%, so both parameters (period_start and period_end) are already well-documented in the schema. The description does not add any parameter-specific semantics beyond what the schema provides, so the baseline of 3 applies.

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 clearly states a specific verb ('returning') and resource ('composite read' for month close), and enumerates the exact contents (P&L, balance sheet, VAT summary, etc.). It also distinguishes itself from siblings by noting it saves round-trips versus calling each report tool separately, so an agent can tell it apart from get_profit_and_loss or get_balance_sheet.

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?

Explicit usage conditions are given: 'Use when the user asks about month-end, how did we do in [month], a period close, or wants a one-shot business health view.' It also implies when not to use it by mentioning the alternative of calling separate report tools. This leaves no ambiguity about when to select this tool.

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