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 meaningful context beyond that: balances are contractual, not cash-paid, results are grouped per currency, and the tool appears gated as 'Pro'. This gives useful behavioral expectations without contradicting the annotations.

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 compact and front-loads the key concept ('The debt at as_of') before enumerating outputs. However, the trailing 'Pro.' fragment is cryptic and the sentence fragment style is slightly telegraphic, though not wasteful.

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 does a good job enumerating what the agent will receive: per-loan outstanding, settled status, next payment, yearly interest/principal, and per-currency totals. It is sufficient for a low-complexity report tool with three optional parameters; it does not need to repeat schema defaults.

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 the parameters are already fully documented. The description reinforces as_of semantics and mentions yearly interest/principal, but it does not add new parameter meaning beyond what the schema provides. Baseline 3 is appropriate.

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 and output: report debt at as_of, per-loan outstanding amount, settlement status, next payment, yearly interest/principal, and per-currency totals. It clearly distinguishes this from sibling tools like loan_list or loan_schedule by emphasizing it is a consolidated valuation/report rather than a list or schedule.

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 the tool is for building a debt/cost report as of a date, but it does not explicitly say when to use it versus siblings such as loan_list or loan_schedule, nor does it state exclusions or alternatives. The context is understandable, but the routing guidance is left to inference.

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