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

Annotations already establish readOnlyHint=true, so the safety profile is covered; the description adds real value by disclosing the derivation method (lognormal at that expiry's ATM IV and forward) and the important limitation that the smile-adjusted figure only applies within quoted strikes. It does not describe output shape or behavior when price/range params are omitted, which keeps it off 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?

Two sentences, no filler, with the core identification front-loaded and the caveat placed last where it belongs. The first sentence is heavily compressed with jargon stacking (lognormal/ATM IV/forward/smile), which costs a little readability.

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 carries the burden of describing return values, and it does so adequately (above/below probabilities, range probability, 68%/90% bands, smile-adjusted value). It stops short of covering default behavior when price or range bounds are omitted, a realistic agent question for a 5-parameter tool.

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 100%, so a 3 is the baseline; the description earns an extra point by framing that all parameters apply to a single expiry and by clarifying that the model is anchored to that expiry's forward and ATM IV, which shapes how price and range inputs should be interpreted.

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 the exact quantity (risk-neutral probabilities from Deribit crypto options), the unit of analysis (one expiry), and the concrete outputs (P(above)/P(below), in-range probability, 68%/90% ranges, plus a smile-adjusted value). This is functionally distinct from the sibling vol/chain/gamma tools even without naming them.

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 only implied via the closing caveat 'Market-implied odds, not calibrated forecasts', which usefully tells the agent what the numbers are not, but there is no explicit when-to-use rule or pointer to alternatives such as options_volatility or options_chain for other option-derived questions.

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