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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered. The description adds real behavior the annotations lack: single-shot execution with no automatic retries or pagination, and an instruction to preserve provider fields and units. It still says nothing about response shape or error behavior, so it is a modest supplement rather than rich context.

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?

It is short and front-loaded, but the opening sentence is pure redundancy with the title, and the semicolon-joined operational rules read as boilerplate rather than tool-specific guidance. Two of three sentences earn their place.

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 no output schema, the description carries the full burden of telling an agent what a detail response contains (ad metrics, creative, product links) and it does not. For a lookup-by-ID tool whose only value is its returned payload, this is a significant omission.

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% and all three parameters are documented in the schema itself (id, country enum, include expansion). The description adds no meaning beyond that, so the baseline 3 applies.

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?

"TikTok Ad Detail" merely restates the tool name and title; it never says what an ad detail actually returns or how it differs from the many nearby siblings (tiktok_ad_search, tiktok_creative_detail, tiktok_ad_related_products). An agent learns only that it is a detail fetch, which the name already conveyed.

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 second and third sentences are operational constraints (no retries, no pagination, preserve units), not usage guidance. Nothing says when to pick this over tiktok_ad_search to obtain the ID, or over tiktok_creative_detail for related objects.

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