compare_carbon_footprint

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

With no annotations at all, the description carries the full burden and does substantial work: it enumerates the returned fields (best-matching SKU, monthly cost, grid-based kg CO2e, market-based residual kg CO2e after renewable matching, power class), the ranking order, and data-provenance caveats like GCP ~64% CFE and OCI unmatched outside EU. It never states data freshness, whether figures are estimates, or whether the call is cached, so the transparency is rich but not complete.

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 core differentiator and the return contract are front-loaded, and every sentence after that adds substantive information about ranking or provenance. The phrase 'the only FinOps tool' is mild marketing framing that could be trimmed, and the run-on sentence packing four return fields plus the power class is dense.

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?

There is no output schema, so the description must describe return values, and it does so thoroughly — fields, ranking, and the renewable-matching interpretation needed to read the numbers correctly. For a 4-parameter comparison tool with no annotations, an agent has what it needs to call and interpret it.

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 only 25% — vcpus, memory_gb, and quantity have no schema descriptions. The description partly compensates by framing inputs as a 'vCPU + memory shape (and optional quantity)' and implying quantity scales the per-cloud result, but it never states units, per-instance semantics, or what targets does beyond the schema's own enum list. Adequate but leaves real gaps at low coverage.

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 and resource ('Multi-cloud carbon footprint comparison') and immediately differentiates itself from the many cost-only siblings: 'the only FinOps tool that returns both USD cost AND kg CO2e/month side-by-side.' An agent can distinguish this from compare_clouds or compare_total_cost_of_ownership without opening a schema.

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?

It gives an explicit trigger condition — 'Use when the user cares about sustainability, Green FinOps, or carbon-cost dual optimization' — which is clear routing guidance. It stops short of naming an alternative to use instead when the user does not care about carbon, so the when-not half is left implicit.

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