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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, so the agent knows this is a non-idempotent state change. The description adds genuinely new context: the operation freezes the chargeback, and the close 'books its work and coding agents', which tells the agent there are downstream effects on cost attribution, plus an explicit confirmation requirement. It stops short of saying whether the freeze is reversible or what happens if the month is still open.

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 clauses, front-loaded with the effect and followed by the confirmation directive; nothing is padded. The phrase 'the close books its work and coding agents' is compressed to the point of being cryptic, costing a little clarity for its brevity.

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 an output schema present, return values need no explanation, and the mutation's core effect and confirmation requirement are covered. Still missing for a non-idempotent mutation: reversibility, behavior when the month isn't finished, and how it differs from approve_month / month_end.

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 0% — the month property has only a regex pattern and no description — so the description must carry the meaning. It does supply the required format (YYYY-MM) and the semantic constraint that the month must be finished, but adds nothing about validation failure modes or how month relates to the chargeback period.

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 concrete action (freezes), a specific resource (a month's chargeback), and a scope qualifier (a finished month, formatted YYYY-MM), so the agent knows the effect is a lock on one month's chargeback. It does not distinguish itself from close siblings such as approve_month, month_end, or month_end_actions, and the shift from the name's 'approve' to the description's 'freeze' leaves the mapping between the two slightly implicit.

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?

'A finished month's' implies a precondition (the month must be complete) and 'Confirm first' is a real usage directive. But it names no alternatives and gives no guidance on what to do when the month is not finished, or when the agent should reach for approve_month or month_end instead.

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