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

Annotations already declare the operation safe, read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds no behavioral context beyond the safety profile—no formula, no assumption about long vs short direction, no handling of invalid entry/stop ordering, and no indication of what the result represents.

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 front-loaded sentence with no filler; the computation comes first and the inputs follow. It is appropriately terse, though it is arguably too terse to convey the constraints that the parameters require.

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 calculator with 0% schema coverage and no output schema, the description should clarify the return value's meaning (quantity vs notional, rounding/lot constraints) and the entry/stop ordering requirement. It omits both, leaving real ambiguity about how to call it correctly.

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 description coverage is 0%, so the description carries the burden for all four numeric parameters. It restates the parameter names in prose ('account balance, risk percent, entry and stop') but adds no units, formatting, expected ranges, or the critical constraint on relative ordering of entry and stop.

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 states a specific computation (risk-based position size) and enumerates the four driving inputs, so an agent knows it's a sizing calculator distinct from a generic math tool. It does not explicitly differentiate itself from the sibling calc_liquidation, but the verb+resource is unambiguous.

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?

There is no when-to-use context, no mention of prerequisites (e.g., that entry and stop must be on the same side/ordered correctly), and no comparison to the sibling calc_liquidation. The agent must infer usage entirely from the name and parameter list.

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