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

With no annotations, the description carries full behavioral burden. 'Atomic' is a genuine behavioral trait that adds real value (all-or-nothing execution). It does not disclose that the operation is destructive and irreversible, what permissions are required, or what happens if some orders are already filled or cancelled.

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?

A single sentence with zero filler. Scope is front-loaded ('Bulk cancel all open orders') followed by the qualifiers and the atomicity guarantee.

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?

A destructive, annotation-free mutation with no output schema deserves more: no statement of irreversibility, no subaccount_id semantics, and no indication of what the caller gets back (e.g. count of cancelled orders). 'Atomic' covers one important concern but not the whole picture.

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 only 33%: market_id is documented in the schema itself ('Omit to cancel across all markets'), and the description restates the user/optional-market scoping. subaccount_id is undocumented in both the schema and the description, leaving a real gap for a 3-parameter tool.

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 with scope: 'Bulk cancel all open orders for a user + (optional) market.' The word 'Bulk' implicitly distinguishes it from the singular sibling pax.cancel_order, but it never names that sibling or draws the contrast explicitly.

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?

Usage is implied by 'Bulk cancel all open orders' — you use it when you want to clear everything rather than one order. However, there is no explicit when-to-use, when-not-to-use, or reference to pax.cancel_order as the alternative for single-order cancellation.

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