get_ou_cost_breakdown

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 implies a read operation ('gives you a clean chargeback report') but does not explicitly state it is read-only, nor does it mention any side effects, permissions, or data freshness. This leaves gaps compared to a tool with annotations.

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 concise: two sentences for purpose/usage, then structured parameter and examples. It is front-loaded with the main action and uses bullet-point style for args and examples, making it easy to scan.

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 simple tool with one parameter and no output schema, the description covers the purpose, use case, prerequisite, parameter, and examples. It is sufficient for an agent to understand and invoke correctly, though return format is not specified.

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 adds meaning to the sole parameter 'days_back' by explaining it as a look-back period in days with a default of 30, which is not present in the schema (which only has title and type). Given 0% schema description coverage, the description compensates well.

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 breaks costs down by AWS Organizational Unit (OU), which is specific and distinguishes it from siblings like 'get_org_cost_summary' or 'get_costs_by_team'. The examples reinforce the purpose.

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 explains when to use (when OUs map to departments/teams for chargeback) and mentions a prerequisite (Team plan with org_reports). It does not explicitly list alternatives but provides enough context for selection among many cost-related siblings.

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