vcf_validate

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

Even though annotations already flag readOnlyHint, openWorldHint, idempotentHint, and non-destructive, the description adds substantial behavioral context: it does not execute, it polls to completion, it resolves the validation twin automatically, and it returns validated true/false plus each failed check. It also covers the edge case for non-conforming targets, which is not derivable from annotations.

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?

The description is detailed but every sentence earns its place. It front-loads the most critical fact ('WITHOUT executing it'), then explains the validation-twin pattern, the return format, the edge case, and finally parameter details in a structured list. It is neither bloated nor under-specified.

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?

Despite having no output schema, the description discloses the return shape (validated true/false plus failed checks) and clarifies the polling behavior. It covers the main usage flow, the automatic twin resolution, and the fallback for targets without /validations. For a tool of this complexity, the description is complete.

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 input schema has zero description coverage for all four parameters, yet the description's Args section clearly explains each: target (appliance name, with guidance on which have the richest surface), path (the actual operation or its /validations path), body (same JSON body as the real operation), and wait_seconds (poll duration). This fully compensates for the schema gap.

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?

The description opens with a specific verb and resource: 'Test a spec against VCF's validation endpoint WITHOUT executing it.' This immediately distinguishes it from execution-oriented siblings like vcf_call. The explanation of validation twins further clarifies the purpose and the relationship to mutating endpoints.

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?

It explicitly frames usage as 'the safe way to iterate on a spec before committing it,' signaling when to use it instead of actual execution. It also describes behavior for targets lacking the standard convention (fallback to listing check-style operations), giving practical guidance. The mention that sddc and installer have the richest validation surface adds targeting advice.

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