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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond the annotations: it explicitly says no requests or notifications are created, describes sampling of a draft match explanation, and notes admin/owner role-chain support and IPP routing for named-person cases. These are meaningful implementation details, even if the return format remains unspecified.

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 two sentences and front-loads the key read-only preview behavior. There is little waste, though the second sentence is cryptic and depends on undefined terms like 'IPP.'

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?

The description covers the core safety behavior and hints at the return value with 'sampled draft match explanation,' but for a complex nested input and no output schema, it leaves important gaps. It does not explain the shape of the returned explanation or how the numerous ApprovalDraft fields affect the preview, so it is minimally adequate rather than 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?

Schema description coverage is 0%, so the description must carry the burden of explaining the nested ApprovalDraft input. It only touches on role chains and IPP routing, leaving most fields such as name, conditions, priority, require_notes, and auto_escalate_after_hours unexplained beyond their names and schema constraints. The description adds some domain context but does not compensate for the lack of parameter descriptions.

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 says it reads a sampled draft match explanation and has no side effects, which gives a general sense of a preview/test operation. However, it never explicitly states that it previews an approval rule, and it does not distinguish this from sibling preview tools such as preview_create_approval_rule or preview_update_approval_rule. The purpose is only implied through the name/title and the ambiguous phrase 'draft match explanation.'

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 no when-to-use guidance and no alternatives. It mentions role-chain support and IPP routing, but it does not tell the agent when to choose this tool over preview_create_approval_rule, preview_update_approval_rule, list_approval_rules, or create_approval_rule.

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