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

Annotations already mark the tool read-only, idempotent, and non-destructive; the description goes further by explaining that it shares implementation with springroll.deploy, that credentials never affect ranking, and that returned alternatives include readiness plus unlock actions. It also discloses that ranking is computed from the public catalog alone and that the receipt matches what a deploy would decide right now. No contradiction with annotations exists.

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?

Three dense paragraphs front-load the core purpose in the first sentence and then add credential independence, deploy equivalence, and usage guidance. There is slight redundancy between 'before any provider account is connected' and the earlier 'without deploying,' but every other 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?

No output schema exists, so the description must convey the return value; it enumerates the receipt contents: provider and plan, monthly cost range, plan limits, what was inferred, and why each other candidate lost. It also explains readiness and unlock actions per ranked alternative, making the tool's behavior before account connection fully understandable.

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 schema already carries the parameter documentation; the description contributes no parameter-level specifics beyond reinforcing that placement hints are provider-neutral and that omitted fields are inferred. This is a solid baseline-3 case where the schema does the heavy lifting.

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?

Opens with a specific action and resource: 'Scores where SpringRoll would place this application and what it would cost.' It immediately contrasts with deploy ('without deploying or writing anything') and names the deploy sibling, so an agent can distinguish preview from actual deployment. The title and description align.

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?

States explicit use cases: 'Use it to put the cost and the limits in front of the user before deploying, or to ask what-if questions by varying the placement hints.' It also explains that it works before any provider account is connected, which is a useful precondition. It does not spell out that actual deployment should go to springroll.deploy, but the 'without deploying' contrast makes that boundary clear.

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