ReftrixMCP

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

Adds substantial context beyond annotations: specifies scoring methodology (0-100 scale), violation classification (severity levels), contrast algorithm (implied by 'checks text/background'), and engine (axe-core). No contradictions with readOnlyHint/idempotentHint 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 dense sentences with zero redundancy. Front-loads the standard (WCAG 2.1) and engine, then details capabilities (violations, scoring, contrast). Every clause conveys distinct functionality (compliance levels, severity classification, score range).

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?

Given 5 parameters with complete schema coverage and safety annotations, the description adequately covers the tool's behavior. Mentions key outputs (score, violations, contrast) despite absence of output schema. Minor gap: could explicitly state that url and html are mutually exclusive inputs in the description text itself.

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?

With 100% schema coverage, baseline is 3. Description enriches parameter understanding by mapping 'url/html' to the audit target, 'level' to WCAG conformance tiers, and 'include_contrast' to text/background validation. Clarifies the mutual exclusivity concept between url and html through 'HTML or URL' phrasing.

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?

States specific action ('WCAG 2.1 accessibility audit'), engine ('axe-core'), and scope (contrast ratio checking, compliance levels). Clearly distinguishes from general 'page.analyze' or 'quality.evaluate' siblings by specifying accessibility-specific methodology and outputs.

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?

Provides clear context (use when checking WCAG A/AA/AAA compliance, need accessibility scores, or contrast validation). While it doesn't explicitly name sibling alternatives like 'page.analyze', the specificity of 'WCAG 2.1' and 'axe-core' makes the appropriate use case unambiguous.

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