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

Annotations say the tool is not read-only, and the description goes further by explicitly warning that the non-dry_run call stores a snapshot and that a later call compares drift against it. This makes the write side effect and the preview escape hatch unmistakable.

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 first sentence packs the core behavior efficiently, and the dry_run caveat is useful and short. The standalone 'Pro.' is cryptic and unexplained, which keeps this from a perfect conciseness score.

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 previews that the call returns exceptions, a trial balance, and bank reconciliation, and it explains the snapshot/drift model. Minor gaps include the lack of a named follow-up tool for drift reporting and no elaboration of what 'Pro.' means operationally.

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?

Input schema coverage is 100%, so the schema already documents month, dry_run, and currency. The description adds no new parameter meaning beyond restating that dry_run writes nothing, which the schema already conveys.

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 names a specific action on a specific resource: it lists unposted/unbalanced items plus trial balance and bank reconciliation, then stores the close as a snapshot. The snapshot/drift behavior is distinctive enough to separate month_close from siblings like trial_balance or period_delete.

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 implies a month-end closing workflow (list exceptions, then store a baseline) and clarifies dry_run as a no-write preview, but it never explicitly names alternatives or states when month_close should be chosen over trial_balance or period_delete. The 'Pro.' tag hints at an access restriction without specifying requirements.

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