Katzilla MCP

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

Annotations already provide readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, covering safety and idempotency. The description adds valuable context beyond this: it discloses the real-time update nature, the specific return structure ('Katzilla envelope'), and details like quality scores and citation with SHA-256 hash for audit, which are not covered by 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?

The description is efficiently structured in two sentences: the first states the purpose and output, the second details the return format and source. Every sentence adds critical information without redundancy, making it front-loaded and zero-waste.

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 has 0 parameters, rich annotations, and an output schema (implied by 'Returns the Katzilla envelope'), the description is complete. It covers purpose, source, update frequency, and output details, providing all necessary context for an agent to invoke it correctly without needing to explain return values redundantly.

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 does not discuss parameters, focusing instead on output semantics. It adds meaning by explaining the return format ('Katzilla envelope') and its components, which compensates for the lack of parameters.

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: 'Get current Ethereum gas prices from Etherscan gas oracle.' It specifies the verb ('Get'), resource ('Ethereum gas prices'), source ('Etherscan'), and output format ('safe, proposed, and fast gas prices in Gwei'), distinguishing it from sibling tools like crypto__etherscan-balance or crypto__etherscan-price which handle different data.

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 implies usage context by mentioning 'real-time' updates and the source 'Etherscan,' suggesting it's for current gas price queries. However, it does not explicitly state when to use this tool versus alternatives (e.g., crypto__mempool-fees for Bitcoin fees) or any prerequisites, which prevents a perfect score.

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