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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: a pricing/allowance model (free within the daily allowance, then $0.002 USDC per call via x402), which is not expressible in annotations and matters for agent cost decisions.

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 tight sentences with the core function front-loaded and the pricing caveat second. Every clause earns its place with no filler.

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 an output schema present, return values need not be explained, and annotations plus full schema coverage handle the rest. The description complements this with pricing context; the only real gap is the unresolved overlap with rxnorm__spelling.

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 100%, so both 'term' and 'limit' are already documented in the schema. The description adds no syntax, format, or ranking details beyond what the schema provides, making the baseline 3 appropriate.

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 ('Ranked RxNorm candidates') plus the input condition (misspelled or partial drug name), so the operation is clear. However, it does not differentiate from the close sibling rxnorm__spelling, which by name appears to serve a nearly identical fuzzy-matching purpose.

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 phrase 'misspelled or partial drug name' implies when the tool is useful, but there is no explicit when-to-use guidance, no statement of when to prefer exact-match tools (rxnorm__rxcui, rxnorm__drugs), and no mention of the likely overlap with rxnorm__spelling.

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