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

Annotations declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and a closed-world scope, which already frame the safety profile. The description adds the pre-persistence framing and the no-network fixture isolation, but it does not disclose side effects such as artifact creation, and it largely echoes mode semantics already present in the schema.

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 dense sentence covering all three modes with the modes front-loaded per clause. It is efficient and front-loaded, though the compressed phrasing ('check inline source before persistence') is slightly elliptical.

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 an output schema present, return values need not be explained, and the description covers all three invocation modes plus the mutual-exclusivity contract. It is reasonably complete for a 5-parameter tool, with only minor gaps around side effects and sibling routing.

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%, so the mode enum, source, revision, fixture_set, and workflow_id semantics are fully documented in the schema itself. The description adds only the high-level mode framing, so the baseline of 3 is appropriate.

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 conveys a specific verb+resource operation ('check inline source', 'check one exact draft revision', 'run fixtures') that aligns with the tool name, so an agent understands it validates workflows rather than running them. However, it never explicitly names the object being validated and does not distinguish itself from siblings like workflow_run or workflow_definition.

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 gives clear context for each of the three entry paths: inline source 'before persistence', one exact draft revision, or 'isolated no-network fixtures'. This effectively tells the agent which scenario maps to which mode, though it offers no explicit when-not-to-use guidance or named alternatives among siblings.

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