Forecast spend, conversions and value for N days (seasonal naive or Holt); needs 14+ days

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the endpoint, modeling options, and the 14+ day history requirement, but it does not disclose auth or rate limits, how models are selected, or return behavior. Beyond annotations, it adds moderate 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?

A single front-loaded sentence with no filler; method options, duration, minimum history, and endpoint are compactly stated. The endpoint parenthetical is the only arguable redundancy, but it is brief.

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 forecasting tool with a nested request body, no output schema, and zero schema descriptions, the definition is incomplete: it does not explain grouping, date cutoffs, currency, client or campaign scoping, or the response. It covers the high-level operation and a key data precondition but not enough for correct invocation.

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% for a nested body with fields such as groupBy, asOf, currency, platform, campaignId, and crossCampaignId. The description only hints at horizonDays ('N days') and historyDays ('14+ days' minimum), leaving most parameter meanings and the required groupBy undocumented.

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 names the specific operation (forecast), the metrics (spend, conversions, value), the horizon (N days), and modeling methods (seasonal naive or Holt). It clearly distinguishes this as the forecasting endpoint, though it does not explicitly contrast it with sibling analytics tools.

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 provides a precondition (needs 14+ days of history), which implies when this tool is valid. However, it gives no explicit guidance on when to use it versus analytics_timeseries, analytics_compare, or other analytics tools, and it does not explain how to choose between seasonal naive and Holt.

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