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

Goes well beyond the destructiveHint/readOnlyHint annotations: it states no funds move, that the action is irreversible, the concrete consequence of cancelling a stop-loss (position left unprotected, re-entry at whatever price is available), and that order-type switches do not block cancellation. These are exactly the side-effect details an agent needs before an irreversible call.

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?

Five tight sentences, front-loaded with what the tool does and the selection rule, then escalating to irreversibility and confirmation guidance. No redundant restatement of the schema.

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?

Mutation tool covered by annotations and a dedicated output schema, and the description still supplies the gap-filling context: side effects, reversibility, parameter exclusivity, and user-confirmation etiquette.

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 already 100%, but the description adds real meaning: the exactly-one constraint, the provenance of each ID, and the schedule semantics ('stops every remaining slice, filled slices stay filled') which the schema does not convey.

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?

Names a specific verb (cancel) and two concrete resources (a resting order or a whole DCA schedule), plus the effect — 'so it can no longer fire'. This is clearly separable from siblings like create_order or get_my_orders.

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 an explicit mutual-exclusion rule ('Pass EXACTLY ONE of `order_id` or `schedule_id`'), routes the agent to the source tools (`get_my_orders`, `get_my_dca_schedules`), and adds a disambiguation instruction to confirm with the user when multiple orders exist.

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