account_security_summary

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

Even though annotations already declare the tool read-only and non-destructive, the description goes further by naming the underlying AWS API calls (sts.GetCallerIdentity, iam.GetAccountSummary, s3control.GetPublicAccessBlock), specifying exact finding thresholds, and detailing the return envelope. This gives an agent a precise model of what the tool will and won't do.

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 organized into 'Collects', 'Findings', and 'Returns' sections, and every line carries useful information. The opening sentence is a compact summary, and the nested detail is front-loaded and easy to scan without being padded.

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?

Given the tool has no parameters and no output schema, the description fully compensates by explaining the return envelope structure, finding severities, and what each collected value contributes. It also covers edge cases like a missing S3 public access block. An agent has all the information needed to invoke and interpret this tool.

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?

The tool has no parameters and the schema description coverage is 100%, so the schema already fully documents the input surface. The description adds no parameter semantics because none are needed; the baseline of 4 for zero-parameter tools applies.

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 clearly states a specific action ('Cheap posture snapshot') on a specific resource ('audited AWS account'), then enumerates exactly what data is collected and which findings are generated. This makes the tool's purpose concrete and distinguishes it from the more specialized audit_* sibling tools.

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 phrase 'cheap posture snapshot' implies a lightweight, account-level overview rather than a deep audit, which provides some usage context. However, the description never explicitly states when to use this tool instead of alternatives like audit_full_posture or audit_root_account_posture, nor does it list exclusions. Usage guidance is implied, not spelled out.

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