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

Annotations already declare the tool as readOnlyHint: true, idempotentHint: true, and destructiveHint: false, so the safety profile is known. The description adds context about the date range scoping ('next 30 days or an explicit date range') but does not disclose other behavioral traits like pagination, rate limits, or return format. With annotations covering the core safety aspects, the description provides some additional value but not extensive transparency.

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 a single, concise sentence that immediately states the core functionality. It is front-loaded with the verb and resource, and every word adds value. There is no repetition of schema or annotation information, and no fluff. Perfectly concise.

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 tool has 5 parameters, 0% schema coverage, and no output schema. The description only mentions the date range concept but does not explain the metric options, granularity, account filtering, or expected output. Given the complexity of an AWS forecasting tool, this description is inadequate for an agent to correctly select and invoke the tool without external knowledge.

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%, meaning the description does not explain any of the 5 parameters (metric, account, end_date, start_date, granularity). The description only hints at date range via 'next 30 days or an explicit date range', but does not specify the parameter names or their formats. The metric and granularity enums are entirely undocumented. Given the low coverage, the description fails to compensate for the missing parameter semantics.

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 clearly states the tool's purpose: 'Get normalized AWS Cost Explorer forecast for the next 30 days or an explicit date range.' It identifies a specific verb ('Get'), a concrete resource ('normalized AWS Cost Explorer forecast'), and a scope ('next 30 days or explicit date range'). This differentiates it from sibling tools like aws_billing_cost (which likely returns historical costs) and aws_billing_anomalies (which deals with anomalies).

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 implies when to use the tool (for forecasting future costs) but does not explicitly state when not to use it or mention alternatives. It does not reference sibling tools like 'aws_billing_cost' for historical data. Clear context is provided, but exclusions and alternative tool guidance are missing.

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