scan_element

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

Describes that axe-core runs on the specified element and its descendants, and returns accessibility scan results. No annotations are present, so the description carries full burden; it adequately discloses the tool's behavior without contradictions.

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 concise: a brief purpose statement, a clear prerequisite note, a parameter explanation with examples, and a return summary. Every sentence adds value, and it is front-loaded.

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 an output schema present (context signals indicate 'Has output schema: true'), the description need not detail return values. It covers the prerequisite, usage, and parameter adequately for a simple 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 only parameter 'selector' lacks schema description, but the description adds 'CSS selector for the element to scan (e.g., '#main-nav', '.form-container')', providing clear semantic meaning and examples.

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 'Scan a specific element on the current page for accessibility issues.' It specifies a specific verb and resource, and distinguishes from the sibling tool 'scan_page' by noting the prerequisite of calling scan_page first.

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?

Explicitly states 'Must be called after scan_page() has loaded a page,' providing clear when-to-use guidance. While it doesn't list alternatives or when-not-to, the context is sufficient for typical use.

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