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

Annotations already declare this a non-read-only, non-destructive, non-idempotent mutation. The description adds real behavioral context beyond that: the operation does not alter waiver or paid state, and after approval the amount/date is locked until an accepted schedule change. It stops short of describing permissions or the response payload, which the output schema covers.

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?

Three sentences, front-loaded with the action and both input formats, followed by the exclusion and immutability constraints. No filler; every clause conveys a distinct rule.

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 mutation tool with an output schema and safety annotations already supplied, the description covers scope, formats, and the post-approval immutability rule. The only real gap is the un-explained scheduleId parameter, which is minor given its UUID format.

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 0%, so the description must carry the load, and it does for two of three parameters: it clarifies that the integer amount is in whole minor units and that the date must be YYYY-MM-DD. scheduleId is left unexplained, though its UUID format makes its role fairly evident.

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 verb and resource ('Record the deposit amount ... and the deposit date') and then explicitly distinguishes itself from the sibling deposit tools by declaring 'This does not waive the deposit and does not mark it paid.' An agent can separate it from waive_deposit and mark_deposit_paid without opening either schema.

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?

Gives clear negative guidance ('does not waive', 'does not mark it paid') and a precondition ('After the schedule is approved, a different amount or date is refused until an accepted schedule change'). It does not name the alternative tools by name for those excluded operations, but the context for use is unambiguous.

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