Katzilla MCP

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

The description adds valuable behavioral context beyond what annotations provide: it specifies the update frequency ('updates monthly'), describes the return format structure ('Katzilla envelope { data, quality, citation }'), and explains what the quality scores and citation contain. While annotations cover read-only, non-destructive, idempotent, and open-world characteristics, the description adds practical implementation details about data freshness and auditability.

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 perfectly concise and well-structured: a single sentence states the core functionality, followed by essential details about source, update frequency, and return format. Every element earns its place, with no redundant information. The bracketed explanation of the Katzilla envelope components is efficiently presented.

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, rich annotations, output schema exists), the description is complete. It covers purpose, source, update frequency, return format structure, and data quality/audit information. With an output schema presumably defining the Katzilla envelope structure, the description doesn't need to explain return values in detail, making this appropriately comprehensive.

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?

With 0 parameters and 100% schema description coverage, the baseline would be 4. The description appropriately notes there are no input parameters needed ('Get daily exchange rates' implies no filtering parameters) and instead focuses on what the tool provides (exchange rates with specific metadata). It adds semantic context about the data source and return structure that the empty schema cannot convey.

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') and resource ('daily exchange rates from the Central Bank of Russia'), and distinguishes it from siblings by specifying the source and data type. It explicitly mentions the source (Central Bank of Russia) and the structured return format (Katzilla envelope), which differentiates it from other economic data tools like economic__exchange-rates or economic__ecb-rates.

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 (for Russian exchange rate data from a specific official source) and implies alternatives through sibling tool names like economic__exchange-rates or economic__ecb-rates for other currency data. However, it doesn't explicitly state when NOT to use it or name specific alternative tools for comparison.

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