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

Goes well past the annotations by disclosing exactly what the mutation produces (one ADJUSTMENT transaction sized to targetBalance − currentBalance), that there is no write when drift is zero, that the amount is denominated in the account's own currency, and that confirmation:true is a hard gate. These are precisely the behavioral facts an agent needs before invoking a destructiveHint=true tool.

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 tight sentences, front-loaded with the action, then mechanism, then the safety gate. No filler and nothing repeated from the schema verbatim.

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 destructive mutation with no output schema, it covers currency, no-op semantics, and confirmation. It stops short of saying what is returned (drift amount, created transaction ID) or whether the adjustment can be undone, which are the remaining unknowns for an agent.

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 100%, so the baseline is 3, but the description adds real meaning: the drift formula clarifies the sign/direction implied by targetBalance and the confirmation gate is restated as a precondition rather than a field. idempotencyKey behavior is left entirely to the schema.

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 (reconcile an account to a target/statement balance) and explains the mechanism — computing drift and creating a single ADJUSTMENT transaction. This implicitly distinguishes it from update_account_balance, but no sibling is named explicitly, leaving the agent to infer the distinction.

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 a clear use condition (account should match a statement/actual balance) and notes the no-drift no-op case, but never names alternatives such as update_account_balance or add_transaction, nor says when reconciliation is the wrong choice. Usage is implied rather than directed.

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