what_is_wasting_money

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

With no annotations, the description carries the burden of disclosure. It openly states what the tool returns (evidence, fix, blast radius, and consequences of false findings), which goes beyond a generic 'find' description. It also mentions credential behavior and the Cost Explorer fallback. It does not disclose performance characteristics or side effects, but for a read-oriented analysis tool, it is reasonably transparent.

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, well-structured, and front-loaded. It uses a clear summary line, a 'Start here' instruction, and a compact parameter list. No wasted words; every sentence earns its place.

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 moderate complexity and the existence of an output schema, the description covers the core aspects: purpose, parameters, and key tradeoffs. It explains why to use Cost Explorer versus CUR and what the findings include. It could optionally mention expected runtime or AWS permissions, but given the output schema and clear context, it is reasonably complete.

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?

All three parameters (profile, cur, repo) are explicitly explained in the description, with default behaviors and tradeoffs. The schema has zero descriptions, so this fully compensates. profile gets credential-chain context, cur gets the s3 URI and the Cost Explorer alternative, repo gets its purpose. This exceeds what the schema alone provides.

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 opens with a specific verb+resource: 'Find avoidable cloud spend on an AWS account.' It clearly outlines what is returned (cost, avoidable items, evidence, fix, blast radius, what breaks), and the phrase 'Start here' establishes its role as the entry-point tool. This distinguishes it from siblings like what_was_not_examined or what_changed, which target narrower subtopics.

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 gives a clear directive to use this tool first ('Start here.') and explains when to use or omit each parameter: omitting cur uses Cost Explorer (no setup, but no per-resource detail), repo has a specific purpose. However, it does not explicitly compare against sibling tools or state when NOT to use it, so it falls short of a full 5.

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