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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so the safety profile is covered. The description adds a genuinely useful behavioral caveat beyond the structured fields: it never recommends a weight, only reports the sweep. It stops short of describing return shape, but the output schema carries that.

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 purpose is front-loaded, followed by routing guidance and parameter notes in a compact block with no filler sentences. Slightly dense run-on phrasing around the output metrics, but every clause earns its place.

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 annotations, a 100%-covered schema, and an output schema, the description only needs to carry intent and routing, which it does fully. The only omission is any hint about result volume or interpretation of the sweep output, which is minor given the output schema exists.

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 100%, so the schema already documents all three params. The description's notes on ticker ('must be one of the holdings') and base ('default USD') largely restate the schema, adding little syntax or behavioral meaning beyond it. Baseline 3 is appropriate.

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 operation (measure one already-held holding at every weight from none to all, rest shared pro rata) and names the exact outputs (volatility, risk share, number of independent bets). It explicitly distinguishes itself from test_a_change and check_before_you_buy, so an agent can route without opening any schema.

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 gives an explicit use case ('how much of this is enough to change anything?') plus two contrasting alternatives with their selecting conditions: test_a_change for one specific change, check_before_you_buy for a holding not yet owned. Nothing about when-to-use vs when-not is left to inference.

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