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

With no annotations provided, the description carries the full burden. It adds meaningful behavioral information: the tool includes maintenance hours often overlooked and reports a 'true break-even volume.' However, it does not disclose assumptions, limitations, or how the estimate is computed beyond that, so the transparency is adequate but not rich.

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?

Two sentences with no filler. The first sentence states the comparison and the key cost component, and the second states the output. Every word earns its place, and the informal 'people forget to cost' adds clarity rather than confusion.

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 simple calculator nature, full parameter schema coverage, and clear two-sentence purpose, the description is largely sufficient. It lacks an explicit return format or exclusions versus sibling tools, but for a tool with no output schema and no annotations, this is a minor gap rather than a blocking one.

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 100%, so the baseline is 3. The description adds conceptual framing for maintenanceHoursPerMonth ('maintenance hours people forget to cost') and for the overall break-even result, but it does not substantially expand on parameter meaning beyond what the schema already states.

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 uses a specific verb ('Compare') and clearly identifies the resource ('paying hosted CI overage against running self-hosted runners'), plus the distinguishing factor of including maintenance hours. It is immediately distinguishable from siblings like calculate_break_even or calculate_github_actions_cost, which are more generic or focused only on cost, not break-even comparison.

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 clearly frames the scenario: comparing hosted CI overage vs self-hosted runners and mentions the 'maintenance hours people forget to cost,' which signals when this tool is relevant. It does not explicitly name alternatives or state when not to use it, but the context is clear enough to guide selection against the sibling list.

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