Reopen Month Close

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

Annotations already declare destructiveHint and idempotentHint, but the description adds valuable context: closing a month doesn't post to the ledger, so reopening is a pure status change with no reversal needed. It also discloses the refusal condition (VAT return submitted) and that the action is confirmation-gated. This goes beyond the annotations without contradicting them.

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 concise at about 120 words and front-loads purpose and usage. Each sentence adds value, though the sentence about closing not posting to the ledger, while useful, could be considered slightly tangential. Overall well-structured and efficient.

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 simple mutation with one optional parameter, the description covers purpose, usage, exclusions, and behavioral nuances. It doesn't specify the success response, but the absence of an output schema and the low complexity make this a minor gap. The refusal condition and confirmation gate are sufficient context for the agent to call it correctly.

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 fully documents the optional period_start parameter, including the default behavior when omitted. The description adds no additional parameter details, which is acceptable given the schema covers it. Baseline 3 applies because the schema does the heavy lifting.

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 the tool undoes a month-end close, using a specific verb ('undo') and resource ('month-end close'). It distinguishes itself from the sibling getters like get_month_close and month_close_summary by being an action, not a read. The synonyms 'reopen', 'unlock', 'undo' further clarify intent.

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?

Explicitly states when to use: when the user asks to reopen/unlock/undo a closed month. It also provides an exclusion: refuses if a VAT return has been submitted, and directs the user to a VAT adjustment instead. This gives clear when-to-use and when-not-to-use guidance with an alternative.

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