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

Annotations only declare readOnlyHint=true, so the description carries extra weight by disclosing what is actually returned: registration status, delegated-stake acceptance, fee factor, consensus public key, and the LSU/claim NFT resources. That is meaningful behavioral detail beyond the annotation, though nothing about errors or address-not-found behavior is covered.

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?

Two sentences, front-loaded with the action and its returned fields, then rounded off with the use case. The enumeration earns its length because no output schema exists to convey those fields.

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 usefully enumerates the returned state and the readOnly annotation covers the safety profile, so an agent knows enough to call it. Minor gap: no indication of failure behavior for an unknown or non-validator address.

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% for both parameters, so the schema already documents the network enum and the validator_ address format. The description adds no format or constraint detail beyond that, which matches the baseline 3.

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 ("Reads a validator from the ledger") and enumerates the state fields it exposes, which makes the scope of a single-validator read unambiguous. It does not explicitly contrast itself with the nearby list_validators or get_component_state siblings, so it falls short of a 5.

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 it to know the current state before proposing a change" gives an explicit usage context, which is more than implied guidance. It stops short of naming alternatives (e.g. list_validators for enumeration) or stating when not to use it.

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