MCP Datadog Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behavioral traits: the temporal availability constraint (current month, available around 12th) and access restrictions (parent-level organizations only). It doesn't mention rate limits, authentication requirements, or response format, but provides substantial operational context for a read-only tool.

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 perfectly concise and well-structured: three sentences that each provide essential information without any wasted words. It's front-loaded with the core purpose, followed by availability constraints, then access restrictions - an optimal information hierarchy.

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 zero-parameter read tool with no output schema, the description provides good contextual completeness: purpose, temporal constraints, and access requirements. It doesn't describe the return format or potential error conditions, but given the tool's simplicity and the absence of annotations/output schema, it covers the most critical contextual information.

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 input schema has 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, focusing instead on operational constraints. A baseline of 4 is appropriate for a zero-parameter tool where the schema fully documents the absence of inputs.

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 projected cost across multi-org and single root-org accounts.' It specifies the resource (projected cost) and scope (multi-org and single root-org accounts), but doesn't explicitly differentiate from sibling tools like get_usage_estimated_costs or get_usage_historical_costs, which prevents a score of 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?

The description provides clear context about when to use the tool: 'Projected cost data is only available for the current month and becomes available around the 12th of the month.' It also specifies access restrictions: 'This endpoint is only accessible for parent-level organizations.' However, it doesn't explicitly mention when NOT to use it or name alternative tools for different cost data needs.

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