validator observations

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered structurally. The description contributes one genuinely useful behavioral caveat — results are sampled and do not establish validator membership — but says nothing about sampling methodology, determinism, or what fields appear in the response.

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?

One short, front-loaded sentence with no padding, but the brevity is under-specification rather than efficiency. The caveat is well-placed, though it occupies the only slot where the actual purpose should have been stated.

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, an undocumented parameter, and a heuristic, probabilistic operation, the description leaves the agent unable to predict what comes back or how to size the sample. For a tool whose whole value depends on interpreting sampled evidence, the definition is substantially incomplete.

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%, so the description carries the full burden for the single parameter, and it never mentions sampling count at all. An agent must infer from the name sampleBlocks that it controls how many blocks are examined; the description adds no meaning about its range, default, or effect on result confidence.

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?

"Sample block author fields" gestures at a verb and resource, but never says what a validator observation actually is or what is returned. Nothing distinguishes it from block_details or chain_status, so an agent cannot tell which sibling to pick without guessing.

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?

The only added clause is a caveat ("not proof of validator membership"), which is about interpreting results, not about when to call this tool. There is no stated trigger condition, prerequisite, or named alternative.

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