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

With no annotations, the description carries the full burden and does substantial work: it defines what a verification means (named human review of identity and domain control), warns that not_registered is common and not a warning, and discloses that the call is free. It does not state what happens when both optional identifiers are supplied or omitted, nor any auth requirement — a modest gap for an otherwise well-disclosed read tool.

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 short sentences, front-loaded with the core purpose and outcomes, then the definitional nuance, then the cost note. No filler; the trailing 'Free.' fragment earns its place as a decision-relevant fact.

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?

There is no output schema and no annotations, yet the description fully enumerates the return states and their meaning, which is the main thing an agent needs. The one gap is ambiguity around the two optional identifiers — which one to pass, and behavior when both or neither are given.

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 params are already documented with example formats. The description adds no guidance on the relationship between domain and public_id — notably that neither is required and which to prefer — so it neither compensates nor detracts. Baseline 3 applies when the schema does the heavy lifting.

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 — checks whether the business behind a domain is verified on the public Lunara register — and enumerates the four possible outcomes. An agent can immediately tell this is a read-only status lookup, distinct from the action-oriented siblings (mission_submit, network_join, redeem, trial).

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?

Usage is implied rather than stated: it is clearly a verification-status check, and 'Free' signals there is no cost barrier to calling it. But it never says when to prefer this over a sibling lookup (e.g. passport_scan) or what circumstances warrant calling it. The interpretive note that not_registered is not a warning is helpful context, not usage guidance.

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