Katzilla MCP

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

Annotations already cover key behavioral traits (readOnlyHint, destructiveHint, idempotentHint, openWorldHint), but the description adds valuable context beyond these. It discloses the source (Gemini Free API), real-time updates, and details about the return structure (Katzilla envelope with quality scores and citation for audit), which are not captured in annotations. No contradiction with annotations exists.

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 front-loaded and efficiently structured in two sentences: the first states the purpose and source, and the second explains the return format and its components. Every sentence adds essential information without redundancy, making it highly concise and well-organized.

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 low complexity (one parameter, simple schema), rich annotations (covering safety and idempotency), and the presence of an output schema (implied by 'Returns the Katzilla envelope'), the description is complete. It adds necessary context about the data source, update frequency, and return structure, filling gaps not covered by structured fields.

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 100% description coverage, fully documenting the single parameter 'symbol' with examples. The description does not add any further parameter semantics beyond what the schema provides, such as format details or constraints. With high schema coverage, the baseline score of 3 is appropriate as the description does not compensate but also doesn't detract.

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 a specific verb ('Get'), resource ('cryptocurrency ticker data'), and source ('Gemini exchange'). It distinguishes from siblings by specifying the data source (Gemini) and the structured return format (Katzilla envelope), unlike generic crypto tools like crypto__coinpaprika or crypto__coinranking.

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 usage: it specifies the data source (Gemini exchange), indicates real-time updates, and mentions the return format. However, it does not explicitly state when not to use this tool or name alternatives among siblings (e.g., crypto__coinpaprika for broader data), so it lacks explicit exclusions or comparisons.

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