AWS MCP Server

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

No annotations provided, so description must carry full burden. It fails to disclose that this is a read-only operation, that forecasts are projections based on historical data, or what format/time range limits apply to the returned forecast data.

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?

Single efficient sentence with zero redundancy. However, given the tool's complexity (5 parameters, nested objects, forecasting logic), it is arguably under-specified rather than optimally 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?

For a 5-parameter forecasting tool with no annotations and no output schema, the description omits critical context: forecast methodology, output data structure, pagination behavior for long forecasts, and AWS service-specific constraints.

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 has 100% description coverage (all 5 parameters documented including nested time_period object). Description adds no parameter-specific guidance, which warrants the baseline score of 3 for high schema coverage.

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 specific verb (Get) and resource (cost forecast) but offers minimal sibling differentiation from aws_ce_get_cost_and_usage despite being in the same Cost Explorer service family. Description is accurate but basic.

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?

No guidance on when to use this tool vs. the historical data tool (aws_ce_get_cost_and_usage), no mention of required IAM permissions for Cost Explorer, and no prerequisites for AWS credentials configuration.

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