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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: prices come from the seller's own page, results are sorted lowest-first, and each entry includes what the test measures. It does not discuss coverage gaps or freshness of pricing, which keeps it from 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?

A single dense sentence, front-loaded with the core purpose and followed by the category breakdown and sort order. Every clause carries information, though the parenthetical asides make it slightly harder to scan than a short bulleted structure would.

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 one required enum parameter, no output schema, and full annotation coverage, the description supplies what an agent needs: what is returned (prices plus what each test measures) and how it is ordered. Minor gaps remain around price currency, region, and recency, which matter for a pricing 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% and the enum is already documented, so the baseline is 3. The description goes beyond it by glossing each value — AMH as egg supply including online-ordered lab blood tests, sperm as at-home tests plus posted lab semen analysis prices, LH for ovulation, hCG for pregnancy — which helps an agent map a user's phrasing to the right enum value.

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 (self-pay prices of fertility tests) with a clear verb-less but unambiguous scope, enumerates the four test categories, and specifies ordering (lowest price first). It is clearly distinguishable from cost-oriented siblings like estimate_ivf_cost or find_ivf_clinic_prices, which cover procedures and clinics rather than tests.

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 enumeration of test kinds implies when the tool applies, and the 'self-pay' framing hints at the uninsured-price use case, but there is no explicit when-to-use/when-not guidance and no named alternative among the sibling cost tools. Usage is inferable rather than stated.

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