Delimit Story Accessibility

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description reinforces this with 'read-only static analysis.' It also adds useful behavioral context beyond the annotations: the scan targets HTML/JSX/TSX and calls backends.ui_bridge.story_accessibility_test. This adds real transparency without contradicting the structured metadata.

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-structured with front-loaded purpose and clear labeled sections. It is slightly longer than strictly necessary because 'Sibling contrast' partially repeats the information already given in 'When NOT to use,' but the organization makes it easy for an agent to parse, so it remains efficient rather than bloated.

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 two-parameter read-only tool with a fully documented input schema, an output schema, and explicit annotations, the description is complete. It covers what the tool does, when to use it, when not to use it, named alternatives, side effects, and scope. Nothing essential for correct invocation is missing.

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%, with both standards and project_path clearly documented in the schema itself. The description does not add parameter-level semantics beyond the schema, so the baseline of 3 is appropriate; it neither improves nor harms parameter understanding.

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 opens with a specific verb and resource: 'Scan HTML/JSX/TSX for WCAG accessibility issues.' It enumerates concrete problem types (missing alt, missing labels, empty buttons, heading order, aria-hidden on focusable elements), and explicitly distinguishes itself from the layout-focused sibling, making purpose and scope unmistakable.

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 gives explicit when-to-use context ('CI gate or pre-merge check on UI changes'), explicit when-not-to-use conditions, and names the exact alternatives (delimit_design_validate_responsive for layout, delimit_story_visual_test for visual regression). This is model routing guidance.

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