audit_trail_posture

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

Annotations already mark readOnlyHint=true and destructiveHint=false. The description adds substantial behavioral detail beyond annotations: exact checks performed, the criticality of zero trails, how multi-region trails are handled, severties for each failing check, and the precise return envelope and finding shape.

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 description is well-structured with purpose, check list, args, and returns sectioned clearly. The bullets are content-dense and every line provides actionable information, with no redundant phrasing.

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 present, the description fully specifies the return envelope, the fields in each finding, severity values, and resource naming. It also explains the default region behavior and the critical zero-trail finding, making it complete for an agent to invoke and interpret results 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 description coverage is 0%, but the description fully compensates by documenting the only parameter 'region', including its default resolution to AWS_REGION or us-east-1. No other parameter information is needed.

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: 'Audit CloudTrail trail posture' and enumerates exact checks. The detailed check list makes it unambiguous and clearly distinguishes it from sibling tools targeting RDS, EBS, IAM, or security groups.

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 intended use case is clear: audit CloudTrail trail posture in the account. It provides helpful context about scope, including shadow trails, but does not explicitly route the agent away from alternatives such as audit_full_posture or account_security_summary.

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