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 genuinely non-obvious behavioral context: a per-call price of $0.002 in USDC via x402 across Base/Solana/Arc, and the important detail that failed calls are not charged — a billing trait an agent cannot learn from structured fields.

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?

Scope and citations are front-loaded, followed by filtering and pricing, so the reader gets the essential framing immediately. The single dense sentence listing covered topics is long but each clause maps to real content, with only minor redundancy between the description and schema on filtering.

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?

An output schema exists, so return-value structure needn't be explained, and annotations cover the read-only nature. The description supplies source scope, citation provenance, filtering behavior, and payment model — enough for an agent to call it correctly; only explicit guidance on when to prefer it over sibling legal/regulatory tools is missing.

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 all three parameters (query, source enum, section) are already documented with examples. The description only restates 'filter by source or words in the text' without adding syntax, matching rules, or precedence between query and section, so 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 resource set with exact citations (USPS Publication 52 §453, DEA 21 CFR Part 1306) and enumerates the topics covered (mailer responsibility, packaging/marking, refills, labeling, telemedicine). This clearly separates it from neighbors like health_dea_controlled_substances or health_usp_monographs_standards, which cover substances or standards rather than mailing rules.

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 sentence 'Filter by source or words in the text' implies how to narrow results, but there is no explicit when-to-use framing, no stated prerequisites, and no named alternative tool for adjacent questions (e.g. controlled-substance scheduling). Usage is inferable rather than guided.

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