SnapAPI MCP Server

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 specific behavioral capabilities (ad/cookie-banner blocking, CSS/JS injection, device emulation, dark mode). However, it omits operational context like error handling, timeout behavior, or whether the tool makes external network requests.

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 sentences efficiently structured: the first establishes core function and I/O, the second enumerates key capabilities. Every phrase earns its place; 'and more' is acceptable given the 18-parameter complexity without being overly verbose.

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 18 parameters, no annotations, and no output schema, the description adequately covers the essentials (input sources, output type, key features) but lacks detail on error scenarios, return value structure, or pagination. The 100% schema coverage compensates for parameter details, but behavioral gaps remain.

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%, establishing a baseline of 3. The description maps capabilities to parameters (e.g., 'full-page capture' to fullPage, 'device emulation' to device) but does not add semantic context beyond what the schema already provides regarding formats, ranges, or validation rules.

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 core action ('Take a screenshot') and resources ('URL', 'HTML/Markdown') with clear output ('return the image'). It effectively distinguishes from siblings like 'pdf', 'video', and 'scrape' by specifying image generation rather than document extraction or video production.

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 clarifies input alternatives (URL vs HTML vs Markdown) implying when to use each, but lacks explicit guidance on choosing this tool over siblings like 'scrape' (data extraction) or 'pdf' (document generation). No 'when-not-to-use' or prerequisite guidance is provided.

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