audit_stale_access_keys

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

The description goes well beyond the readOnly/destructive annotations by disclosing that it scans every IAM user, flags only Active keys over the threshold, returns a specific shape with findings and scanned, and computes severity based on MFA presence. This gives the agent a clear model of behavior and side effects.

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 compact and front-loaded: the first sentence states the core purpose, the second describes behavior and return value, and the third covers severity. Each sentence adds necessary information without redundancy or padding.

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?

For a single-parameter read-only audit tool with no output schema, the description is fully sufficient: it details what is scanned, what is returned, and how severity is assigned. The agent can invoke and interpret the result without additional context.

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?

Although the schema provides no parameter descriptions for max_age_day, the description explicitly explains its role as the age threshold and default value, making the parameter's semantics clear. It does not detail edge cases like zero or negative values, but the basic meaning is sufficiently covered.

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 uses a specific verb ('Audit'), a clear resource ('IAM users'), and a precise condition ('active access keys older than max_age_days'). It unambiguously distinguishes this tool from siblings like audit_users_without_mfa or audit_full_posture.

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 description clearly identifies the intended scenario: auditing IAM users for stale active access keys, and explains the threshold and severity logic. It does not explicitly name alternatives or exclusions, but the context is strong enough for an agent to select it appropriately.

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