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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint, so the safety profile is covered. The description adds real behavioral context beyond that: cache-only sourcing from tiktok_insights_daily, the 1-20 scope ceiling, and that custom attribution windows are rejected at the server.

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?

Purpose is front-loaded, then attribution, required fields, date-param gotcha, and a concrete example, each on its own labeled line. Dense but zero waste, and the ordering matches how an agent would construct the call.

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 an 11-param, no-output-schema tool it covers the call-critical pieces (group_by, scopes, dates, attribution) and an example. It remains incomplete on pagination, sorting, view_mode and consistency, and the group_by/product_id discrepancies against the schema could actively mislead.

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 0% across 11 params, so the description must carry the load. It documents group_by, the scopes[] shape, and the date_from/date_to naming gotcha, but leaves page, page_size, sort_dir, sort_key, view_mode, consistency, connection_context and require_complete_range unexplained. Worse, it lists group_by as {account, campaign, adset, ad} (omitting the schema's ad_group) and claims a product_id scope filter that the schema explicitly does not expose.

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?

States a specific verb and resource: a server-side batch overview that compares multiple explicit scopes, reading cache-only from tiktok_insights_daily. The batch framing inherently distinguishes it from single-scope siblings like insights_query_overview, but no sibling is named explicitly, so it falls short of a 5.

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?

Gives clear context: use it for comparing multiple scopes without client-side concurrent fan-out, with constraints on attribution (omit or use value; custom windows rejected) and the 1-20 scope limit. It stops short of explicitly stating when to prefer this over insights_query_overview or insights_query_consistent.

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