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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description adds real value on top: a hard cap of 10 reports per call, the x402 payment rails (Base, Solana, Arc), the $0.002 per-successful-call charge, and that failed calls are free. It does not mention data recency/lag or FAERS coverage window, which keeps it short of 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?

Roughly four sentences, front-loaded with the resource and return fields, then caveat, then cap, then price. Every sentence carries distinct information with no repetition of the title.

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 two-parameter lookup with an output schema already defining the payload, the description supplies everything an agent needs: input constraint, result cap, causal-interpretation caveat, and the cost/payment model before the call is made.

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 parameters are already documented in the schema. The description reinforces the 'generic drug name' constraint and the 10-report ceiling but adds no syntax, normalization, or format detail beyond what the properties already state; 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?

Names a specific verb and resource (FDA FAERS drug adverse event reports via openFDA) and enumerates the returned fields (report ID, receive date, seriousness, patient age/sex, drugs, reactions). It also fixes the input domain to a generic drug name, which cleanly separates it from siblings like health_drugbank_interaction or health_fda_recalls_enforcement.

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 description constrains the query to a generic drug name and warns that spontaneous reports do not prove causation, which implies appropriate interpretation. However, it never states when to prefer this over alternatives (e.g., EMA or drugbank sibling tools) or any prerequisites beyond the payment note.

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