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

Annotations already cover safety (read-only, idempotent, closed-world, non-destructive), and the description adds useful context beyond them: the values are computed rather than authoritative raw data, and the exact metric set returned is enumerated. Minor gap: no note on precision/rounding or what happens on an invalid or non-existent id.

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-loaded with the value proposition and then a tight enumeration of outputs; no filler sentences. The single long sentence is dense but each listed metric earns its place by substituting for a missing output schema.

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 one-parameter read-only tool with no output schema, listing the returned metrics plus their source tools is nearly sufficient. The only meaningful omission is disambiguating the 'id' parameter.

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% for the single 'id' parameter, which only carries a numeric pattern. The description implies the id refers to one offer via 'one offer' and 'Computed from get_offer', but never states explicitly that the id is an offer identifier or what format it takes, leaving a small gap the schema does not close.

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+resource ('plain-language economics of one offer') and enumerates exactly what is covered: buyer cost/payoff, breakeven per token, max loss/payoff, seller proceeds after fees, exercise fee, time left. This clearly distinguishes it from get_offer (raw record) and get_prices (price data) because it declares itself a derived, human-oriented summary.

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?

'Computed from get_offer and get_prices' tells the agent this is a derived view and implies it should be preferred over manually combining those two tools. It does not explicitly state when to use get_offer/compare_offers instead, so there is no full when/when-not routing.

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