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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent), and the description adds real value beyond them: 'selected' patterns signals partial coverage, and the note that intrinsic functions are flagged for human review rather than resolved is an important behavioral limitation. It stops short of saying what happens to unrecognized resources or how findings are presented.

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 short sentences with no filler. The purpose is front-loaded and the intrinsic-function caveat follows immediately after, so every clause 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?

An output schema exists, so return values need not be described, and annotations carry the safety story. What remains thin is the definition of 'selected risky patterns' — an agent cannot predict which findings it will get — but the description is otherwise sufficient to call the tool correctly.

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 coverage is 0%, so the description must compensate, and it partially does: 'CloudFormation JSON template' tells the agent the parameter is the template body itself (an object), not a YAML string or S3 URL. It adds nothing about the shape of that object or what key patterns are inspected, leaving the single required parameter thinly specified.

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 (Review) and resource (CloudFormation JSON template) with defined scope ('selected risky configuration patterns'). The resource type alone separates it from terraform_plan_review, kubernetes_manifest_review and iam_policy_review in the sibling list, though no sibling is named explicitly.

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?

Usage is only implied by the verb 'review' — an agent can infer this is a static pre-deployment check on a template. There is no explicit statement of when to reach for this versus the other *_review siblings, and no prerequisites or exclusions.

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