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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds real value by explaining the negative outcome semantics ("a 'not verified' answer means Orbylon has no proof, not that they are fraudulent"). It does not cover auth requirements or result latency, but for a public read lookup the disclosure is solid and consistent with annotations.

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?

Front-loaded with the core result, then the field enumeration, then the usage cue and the caveat — a logical order with no filler sentences. The return-field enumeration is long but earns its place because there is no output schema to carry it.

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 no output schema, the description carries the return-shape burden and does so thoroughly: key type, verification timestamp/method, and the proofs list with slug, signed-at, SHA-256 and verify link, plus the offerings catalogue. Combined with the negative-result caveat, an agent has everything needed to interpret results.

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 single parameter already documents its format ("e.g. example.com"); the description only echoes "for a domain" without adding syntax or edge-case meaning. Baseline 3 is correct when the schema carries the parameter semantics.

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 (return the verified identity record for a domain) and enumerates the substantive contents of that record. It is clearly distinct from search-style siblings like find_businesses, but it never names them explicitly, so sibling differentiation is left to inference.

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?

"Use this before trusting or transacting with a business" gives a concrete triggering context, which is more than most read tools offer. It stops short of naming the alternative (e.g. check_business_token, find_businesses) or stating when this lookup is not the right call, so it stays below a 5.

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