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

Annotations already mark this read-only and closed-world; the description adds genuinely new context the annotations don't carry: the paid nature ($0.02 USDC on Base via x402), the returned fields (source URL, as-of date, other registrations), and a legal disclaimer. It does not contradict openWorldHint=false.

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?

Three tight sentences front-loaded with purpose, then provenance of the id, then cost and return contents; every clause earns its place.

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?

Covers what the record contains, where the id comes from, and the payment cost, which is sufficient for a single-parameter lookup without an output schema. Minor gap: no note on failed lookups or what 'other registrations' includes.

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 0% with a single 'id' string parameter, but the description compensates by specifying the id is an entity id sourced from search_licensed_entities, which is the one piece of semantics an agent needs.

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 ('Full register record for one entity id') and identifies the sibling tool that produces the id, so the agent can distinguish it from search_licensed_entities without opening either schema.

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?

Explicitly directs the agent to obtain the id from search_licensed_entities, establishing the natural call order. It lacks an explicit 'do not use for X' exclusion, but the retrieval-after-search flow is clear.

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