tactual-mcp

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

With no annotations provided, the description carries the full burden and discloses key behavioral traits: read-only safety ('does not modify pages'), partial failure handling ('If a single URL fails...remaining URLs still complete'), session behavior ('single browser session'), and output characteristics ('~200 bytes per page').

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 tightly constructed paragraphs with zero waste. First paragraph establishes purpose, mechanism, and safety; second provides usage guidance, output expectations, and error handling. Every sentence conveys distinct information.

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?

While the description effectively compensates for the missing output schema by detailing return size and structure, it fails to specify the domain of analysis (accessibility testing implied by 'AT profile' and 'sr' in default values, but never stated), leaving a significant contextual gap for an otherwise complex 6-parameter 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?

Input schema has 100% description coverage (all 6 parameters documented), establishing a baseline of 3. The main description text does not add parameter-specific semantics (e.g., explaining 'AT profile ID' or providing URL format examples), but none is required given complete schema coverage.

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 explicitly states the tool 'Analyze[s] multiple pages and produce[s] an aggregated site-level report' and distinguishes itself from the sibling analyze_url by noting it combines results into a 'site score with per-page breakdown' and runs 'in a single browser session.'

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 explicit guidance: 'Use this instead of calling analyze_url repeatedly when you need a site-level assessment.' This clearly defines when to prefer this tool over its sibling alternative.

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