unphurl-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key traits: it's a read-only operation (implied by 'Show'), discloses that no API key is required, and adds context about credit consumption patterns (e.g., most lookups are free, typical usage rates). It does not cover aspects like rate limits or error handling, but provides sufficient operational context for a tool with no parameters.

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 and front-loaded: the first sentence states the core purpose, followed by a bulleted list of packages for clarity, and additional context sentences that earn their place by explaining credit usage and authentication. There is no wasted text, and each part adds necessary information efficiently.

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 the tool's simplicity (0 parameters, no annotations, no output schema), the description is largely complete. It covers purpose, usage context, behavioral traits, and output details. However, it lacks explicit information on the return format (e.g., JSON structure) and error cases, which could be helpful for integration. For a no-parameter tool, this is a minor gap.

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 input schema has 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately focuses on output semantics by detailing what is returned ('all packages with credit counts and prices') and listing package specifics. It adds value beyond the schema by explaining the return content, though it does not fully describe the output structure (e.g., format).

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 the tool's purpose with specific verbs ('Show available pipeline check credit packages and pricing') and resources ('credit packages and pricing'), distinguishing it from siblings like get_balance (which shows current credits) or purchase (which buys credits). It explicitly lists the packages with details, making the purpose concrete and actionable.

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 provides clear context for when to use this tool: to view pricing packages before purchasing credits. It implies usage by stating 'Most URL lookups are free... Credits are only consumed when...' and 'This tool does not require an API key,' guiding users on prerequisites. However, it does not explicitly mention when not to use it or name alternatives like get_balance for checking existing credits.

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