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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), and the description goes well beyond them: it discloses the embargo visibility rule, the `unlock` {kind, ref} structure tied to product_checkout, the Bearer JWT auth requirement, and a prompt-injection warning that mints/symbols/reasons are third-party DATA. It does not state the embargo default or rate limits, keeping it short of a 5.

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 core payload is front-loaded in the first sentence, and subsequent sentences cover visibility, safety, and auth compactly. The opening sentence is a dense field enumeration, but since there is no output schema that information earns its place; structure is only mildly cramped.

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 correctly supplies the return shape via its field list, and it covers auth, embargo visibility, and the safety caveat for a one-parameter tool. It is essentially complete, with only minor omissions such as the embargo default and how `unlock` refs are resolved.

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?

There is a single parameter with 100% schema description coverage, including an example arm id, so the schema carries the semantics. The description references the arm only obliquely ('a desk lab arm's last scheduled run') and adds no format or constraint detail beyond the schema, matching the baseline 3.

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 resource and payload: the buys/sells an arm's last scheduled run planned, with an explicit field list (side, mint, symbol, usd, fraction, reason, exit method, when, run id). That is far more specific than the title alone. It does not, however, explicitly differentiate itself from siblings like desk_board or desk_strategy_submit, so it stops short of a 5.

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?

It explains access tiers (owner/buyer get live signals; others see only entries older than embargo_secs) and that a Bearer JWT unlocks what you own or bought, which implies when the tool is usable. But it names no alternative tool or condition for choosing this over a sibling, so usage guidance is implied rather than explicit.

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