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

Annotations already declare readOnlyHint=true, so the safe-read profile is covered and the description need not restate it. The description goes beyond that by disclosing the per-operation metadata returned (owner-badge requirement and transaction-sharing compatibility), which is genuine behavioral content. It does not mention pagination or caching, but for a static catalog listing that gap is minor.

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?

A single sentence, front-loaded with the verb and resource, followed by the enumeration and the two returned flags. The long parenthetical list is dense but each item is an operation name the agent would otherwise have to discover; it earns its space, though it could be trimmed.

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 parameters and no output schema, the description carries the return-value burden and does so: it names the operation set and the two boolean attributes per entry. An agent can decide to call it and interpret the result without further documentation.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline is 4. The description correctly implies a no-argument, full-catalog call rather than introducing filtering semantics that do not exist.

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 (Lists) and a precise resource (every operation a validator supports), then enumerates the operation set so the agent knows exactly what will be returned. It is clearly distinguishable from siblings like list_validators or get_validator_state, which operate on validators, not on the operation catalog.

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 states usage timing: 'Use it before build_validator_manifest,' which names the downstream sibling and the sequencing condition. It does not state when not to use it or cover the other alternative paths, but the primary routing guidance is unambiguous.

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