compare_total_cost_of_ownership

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly states the tool uses linear YoY growth assumptions, a configurable horizon (default 3 years), and returns cumulative TCO, year-by-year breakdown, and sensitivity analysis. It also notes it computes from a public catalog, but does not mention if it modifies data or requires authentication.

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 (three sentences), front-loaded with the primary action ('Project per-cloud per-year cost'), and efficiently conveys key outputs and use case. It could be slightly tighter but is well-structured.

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 (11 parameters, nested objects, no output schema), the description provides adequate context for purpose and outputs but lacks details on default behavior (e.g., what happens with empty inputs) and output structure beyond brief mentions. It meets minimum viability but has gaps.

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 description coverage is very low (18%), and the description does not compensate by explaining individual parameters. It provides high-level context about growth assumptions and horizon but does not describe the meaning of arrays like compute, storage, egress, or their nested fields. The agent would need to infer from parameter names.

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: 'Project per-cloud per-year cost over a configurable horizon' and details the outputs (cumulative TCO, breakdown, sensitivity analysis). It distinguishes itself from sibling tools like compare_clouds (likely static) and assess_migration (likely migration-focused) by focusing on future cost projection with growth assumptions.

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 mentions the use case: 'The kind of number that goes into board decks and budget conversations,' providing clear context for when to use this tool. However, it does not explicitly exclude alternative tools or state when not to use it, so it falls short of a perfect score.

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