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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so "Saves nothing" largely restates the structured safety profile rather than extending it. The description does not say what a failed validation yields, whether partial configs are tolerated, or what the preview contains — and there is no output schema to fill that gap.

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 short clauses, front-loaded with the action and immediately followed by the effect bound. Nothing is wasted, though the brevity may be under-specification rather than discipline.

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?

For a one-parameter, read-only validation tool with full annotations and no output schema, the essentials are covered: what it does and that it has no side effects. The remaining gap is what the preview returns, which the absence of an output schema makes more costly than it would otherwise be.

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% for the single parameter, so the schema carries the burden and baseline 3 applies. The description adds no meaning about the config shape or which fields are valid — notably, the schema's "using listed fields" points at fields that are listed nowhere in this definition.

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?

"Validate and preview a block config" states a specific verb pair and resource, and "Saves nothing" bounds the effect. It is distinguishable from report_add_block and report_update_block even though neither sibling is named.

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?

"Saves nothing" implies this is a dry run before add/update, but that inference is left to the agent. There is no explicit when-to-use statement, no prerequisite (does the config need a valid report/dashboard context?), and no named alternative.

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