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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds behavioral context by revealing the scan reports current level, passing checks, and failing checks with fix strings, and notes it is a re-scan of the live site. This goes beyond annotations by specifying output content and the post-deploy framing, though it doesn't mention rate limits or edge cases.

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?

Three sentences, each earning its place: first gives the usage trigger, second describes the action and outputs, third distinguishes from scan_site. The description is front-loaded with 'Use this after...' and contains 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?

With a simple 2-parameter schema and an output schema present, the description covers the core usage context, behavioral output, and sibling relationship. It doesn't explain how expectedLevel is used if omitted or behavior on invalid URLs, but the output schema and annotations cover enough for a well-scoped verification 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?

Schema description coverage is 0%, so the description must compensate. It partially defines expectedLevel ('expected level') and url ('the live site') through context, but does not explicitly describe parameter formats, types beyond the schema, or examples. It adds some meaning but leaves room for ambiguity, especially for expectedLevel's optional nature.

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 the tool's function: 'confirm the live site reaches the expected level' and 'Re-scans the site, reports current level, which checks pass, and which still fail with their fix string.' It explicitly differentiates from sibling scan_site by framing as post-deploy verification rather than initial assessment, providing a specific verb+resource with clear scope.

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 guidance is provided: 'Use this after a customer has deployed the agent-ready files...' It also names an alternative tool (scan_site) and explains the distinction: 'Same scanner as scan_site, but framed as post-deploy verification rather than initial assessment.' This clearly orients the agent to choose this tool over siblings.

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