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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered; the description adds the non-obvious behavioral promise that validation 'Returns field-level errors without modifying any flow.' It does not describe error shape or which configs are out of scope, but this is solid added context beyond the 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?

Two tight sentences, behavior first (returns errors, no mutation) and routing second (use before update calls). No filler, no restated name, front-loaded with the key semantic fact.

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 10-parameter validation tool with no output schema, the description covers purpose, safety, and call ordering, and the schema covers the field-conditionality. It could say more about the return/error format since there is no output schema, which is the only meaningful gap.

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% and the schema descriptions for the 10 parameters (stepType enum, per-type fields like sourceCode, packageJson, loopItems) are rich and conditional. The description adds nothing about parameters, so the baseline 3 is correct: the schema does the heavy lifting.

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?

Specific verb (Validate) plus resource (step configuration), and it explicitly distinguishes itself from siblings by naming ap_update_step and ap_update_trigger as the operations to run afterward. The read-only, error-returning nature of the operation is unambiguous.

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?

States the exact when-to-use condition ('before applying it', 'before calling ap_update_step or ap_update_trigger') and makes the alternative path explicit. An agent knows precisely when to reach for this tool versus updating directly.

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