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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context beyond that: volatility is a required manual input because there is no live implied-vol market to pull it from, and the payout is settled at a fixed close time. It does not discuss rate limits or failure modes, but for a pure calculation tool this is solid.

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?

Front-loads purpose before the model/target-market detail, and every paragraph segment earns its place (instrument definition, routing, input requirement, return fields). It is dense and somewhat long, but not padded or repetitive.

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?

There is no output schema, and the description compensates by enumerating the return fields (d1, d2, probAbovePct, probBelowPct, fairPriceAboveCents, fairPriceBelowCents) and the cents convention that makes them comparable to venue quotes. Combined with full schema coverage and annotations, nothing needed to call the tool correctly is missing.

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 the schema already documents all five parameters. The description reinforces why volatilityPct is mandatory and confirms the cents convention, but adds little syntax or format detail beyond the schema, so the baseline 3 applies.

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 — theoretical fair value for a time-windowed crypto up/down contract — and pins down the exact instrument family (ADI Predictstreet / Kalshi-style daily crypto markets) and pricing model (cash-or-nothing digital, N(d2)). It explicitly distinguishes itself from the live-market odds sibling, so an agent can route to it without opening the 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?

Gives an explicit when-to-use condition ('no live market price to read, e.g. zero trading volume') and names the alternative it is preferred over ('instead of a live-market odds tool'). It also supplies example user phrasings, leaving nothing to inference.

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