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

With no annotations, the description carries full responsibility for behavioral disclosure. It clearly states return values (PASS/FAIL/REVIEW with node and field, reason codes, evidence packet), pricing by mode, the default fallback, and the error behavior for missing payment signature. It does not explicitly state whether the tool is read-only or whether repair modifies resources, but the description of repair as producing an RFC 6902 JSON Patch implies it returns a patch rather than executing it, which is useful. Minor gap: no explicit mention of side effects or idempotency, but overall behavior is well disclosed.

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 longer than average but every sentence carries meaningful information: purpose, modes, return format, scope restriction, input format, pricing, default behavior, and payment handling. It is structured logically and front-loaded with the core purpose. It could be slightly tightened, but it is not wasteful.

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?

Given the tool's complexity (three modes, pricing, payment requirements, error handling, return format), the description covers everything an agent needs: how to call it, what each mode does, pricing implications, default behavior, and expected outputs. There is no output schema to rely on, so the description fully compensates by describing the return structure. Nothing critical is missing for correct invocation.

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 schema already documents both parameters at 100% coverage, with the query parameter described as a JSON string with mode and inputs. The description adds significant value by providing an example structure, enumerating the modes, explaining the meaning of each mode, and clarifying that mode is read from query (not context). This goes beyond the basic schema and helps an agent construct correct inputs and choose the right mode.

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 'Validate and repair an n8n workflow JSON before production,' which states a specific verb (validate and repair), a specific resource (n8n workflow JSON), and the context (before production). It further distinguishes itself from siblings by explicitly limiting to n8n only and describing three distinct modes. No sibling tool even comes close to this functionality, so it is easily separable.

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 description provides explicit when-to-use instructions: 'before production' and 'n8n only.' It details how to invoke each mode (static, simulated, repair) and includes a default mode if mode is missing. It also explains the payment challenge and the error returned without a payment-signature header. This is comprehensive guidance with clear conditions and no ambiguity.

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