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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds meaningful semantic context by defining 'fixed policy baseline' (compliance requirements) and excluding drift/regression analysis, which prevents misuse and clarifies the tool's scope. No contradiction with annotations.

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 sentences, front-loaded with the core action ('Compare...'), followed immediately by usage guidance with alternative tool names. No redundant or filler content.

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?

The tool has a nested baseline object and no output schema, but the description plus rich schema provide sufficient context for selection and invocation: it explains the compliance purpose, explicitly excludes drift and multi-domain comparison, and the schema fully documents parameters. A minor gap is not describing the output format, but this is partially mitigated by the 'format' parameter.

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 domain, baseline (including all nested require_* flags, max_* fields, grade/score floors), format, and force_refresh are fully documented. The description text does not add parameter-level detail, but the schema carries the burden, so baseline 3 is appropriate.

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 states a specific verb+resource+outcome: 'Compare a domain's current security configuration against a fixed policy baseline to determine compliance.' It also distinguishes from sibling tools by explicitly naming analyze_drift and compare_domains for other use cases.

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?

Explicit when-to-use and when-not-to-use guidance is provided: 'Use to check whether a domain meets a policy requirement — not for tracking improvement/regression over time (use analyze_drift) and not for comparing multiple domains (use compare_domains).' The schema's baseline description reinforces this by clarifying the baseline is a policy object, not a prior scan.

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