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

Annotations already declare read-only, idempotent and open-world behavior, so the bar is lower. The description adds the meaningful caveat that data is delayed and enumerates the returned fields, but says nothing about rate limits, pagination, or coverage when strikes surpass available listings.

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 that packs scope, returned fields, data delay and the expiration default without filler. It is dense but readable, and nothing is wasted.

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 explaining return values, and it does so by enumerating per-strike fields plus available expirations. It is largely complete for a simple read tool; only symbol format and behavior at range limits go unmentioned.

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 67% and both optional parameters are already documented in the schema. The description adds the useful clarification that strikes are relative to the current price, but the 'omit expiration for nearest' line merely repeats the schema default.

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 resource and scope: one expiry of a US stock's option chain with per-strike call/put metrics. It is clear what the tool returns, but it never distinguishes itself from plausible siblings such as market_query or my_option_expirations, so it falls short of 5.

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?

The only usage guidance is the embedded rule 'Omit expiration for the nearest,' which is an implied default rather than a when-to-use statement. There is no indication of when to prefer market_query or my_option_expirations instead.

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