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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered; the description adds that the created template is private and that template.requestId enables safe retries. That retry/idempotency-key guidance is genuinely useful context beyond the structured fields, though it sits in mild tension with idempotentHint=false (retries are only safe when the caller supplies requestId, not by default).

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?

Three compact sentences: the action leads, the retry mechanism follows, and the exclusions close. No filler, and the most important information is front-loaded.

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?

An output schema exists, so return values need not be described, and the nested input schema is fully annotated. The description covers purpose, side-effect scope and exclusions adequately; it could go slightly further by naming the sibling to use for draft/modification flows, but nothing an agent needs to call it correctly is missing.

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 nested configuration is documented inline, so the schema carries the field-level detail. The description still adds meaning by summarizing the template contents (questions, response settings, attachments, method) and by explaining the purpose of requestId as a retry-safety key, which the schema only calls a 'stable requestId'.

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 ('Creates a private Custom template') and enumerates the payload it carries (questions, response settings, attachments, method). It also differentiates from siblings by negation ('Does not change existing templates, create a draft or start research'), separating it from update_study_template, save_study_draft and start_study_run.

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 exclusion guidance — not for modifying existing templates, not for drafts, not for starting research — which implicitly routes the agent away from save_study_draft, update_study_template and create_study/start_study_run. However, it never names those alternatives explicitly, so the agent must infer which tool to reach for instead.

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