AWS FinOps MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states what the tool does ('find'), not how it behaves. Missing are details like: whether this is a read-only operation, what authentication is required, how results are returned, time range considerations, or any rate limits. The description doesn't contradict annotations (none exist), but provides minimal behavioral 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?

The description is extremely concise at just 5 words. It's front-loaded with the core purpose and contains no unnecessary words. Every word earns its place, making it efficient for quick understanding of what the tool does at a high level.

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?

Given the tool's complexity (7 parameters, AWS authentication, EventBridge analysis) and the presence of an output schema, the description is insufficient. While the output schema may cover return values, the description doesn't address authentication requirements, time period considerations, regional scope, or how 'no invocations' is determined. For a tool with this many parameters and no annotations, more context is needed.

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?

The description mentions no parameters at all, while the schema has 7 parameters with 0% description coverage. Parameters like 'period', 'profile_name', 'role_arn', and authentication credentials are completely undocumented in the description. This fails to compensate for the schema's lack of parameter descriptions.

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: 'Find EventBridge rules with no invocations.' It specifies the verb ('find') and resource ('EventBridge rules'), and distinguishes from siblings by focusing on unused rules rather than other AWS resources. However, it doesn't explicitly differentiate from other 'find_unused_' tools beyond the resource type.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, related tools for analyzing EventBridge rules with invocations, or context about why finding unused rules is valuable. The user must infer usage from the tool name alone.

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