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

With readOnlyHint=false and idempotentHint=false already signaling a non-idempotent write, the description adds useful behavioral context beyond annotations: it discloses that providing an account also writes the cash row ticket and that the amount is the total before fee. It does not contradict 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 a single dense sentence with no filler, front-loading the core action and then compactly listing optional inputs and side effects. The parenthetical about the cash row is slightly compressed but still earns its place because it explains an important non-obvious behavior.

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?

Given the output schema exists and the annotations already communicate the write/non-idempotent nature, the description is largely complete for correct invocation: it names required inputs, clarifies amount semantics, and discloses the conditional cash-row effect. A minor gap is the lack of guidance on edge cases like holding ambiguity or duplicate recording, but that is not essential for a straightforward call.

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 63%, and the description reinforces some parameter meanings (amount before fee, optional fee, optional account causing a cash row), but much of this repeats the schema's existing descriptions. Parameters like date and note are not elaborated in the description, and kind is only implied by "buy or sell," so the description adds some but not extensive value beyond 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?

The opening phrase "Record a buy or sell of a holding" gives a specific verb, resource, and action, making it immediately distinguishable from sibling write tools like record_settlement or record_loan_payment. It also lists the key inputs (quantity, amount, fee, optional account) and the notable side effect of writing a cash row, leaving no ambiguity about what the tool does.

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 clearly states when to use the tool: to record buy or sell events for a holding. However, it does not explicitly mention when not to use it or point to alternatives such as log_transaction for general cash movements or create_transfer for pure transfers, so an agent must infer the boundary from sibling names and the holding-specific language.

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