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

Annotations already cover the read-only/idempotent/non-destructive profile, and the description adds substantial context beyond them: data provenance (AWS Cost Explorer, Azure Advisor, GCP Recommender), that commitment rows omit instance-type fields, that only one term/payment/lookback variant is surfaced (AWS 30-day, 1-year, no upfront default), and the currency split between per-recommendation figures and the USD total.

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?

Front-loaded with the core purpose in the first clause, and nearly every sentence carries non-obvious information. The middle section on commitment variants and provider defaults is dense and longer than needed, but the content is load-bearing rather than filler.

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?

With no output schema, the description must carry the return-shape burden and does: it explains the `type` values, the commitment-row field differences, where term/payment/lookback live, and how currency is reported. An agent can interpret and report results correctly without further documentation.

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?

Zero input parameters, so the baseline is 4 regardless of schema coverage. The description goes further by documenting the returned `type` enumeration and the presence of `detail`, `currency` and absent instance-type fields, which meaningfully describes the payload an agent will receive.

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?

States a specific verb and resource ('List active cost-reduction recommendations') and immediately bounds the scope: 'for this account', sourced from provider engines rather than computed by Plutus. It is clearly distinguishable from siblings like list_tag_recommendations and list_commitment_expirations.

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?

Gives clear context for interpretation — the four `type` values, what commitment rows represent, and an explicit caution not to report the single surfaced commitment variant as the only option. It does not, however, name when to prefer this tool over overlapping siblings such as list_commitment_expirations or list_commitment_utilization.

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