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

Annotations already indicate read-only, idempotent, open-world, and non-destructive behavior. The description adds the context that this is a directory/reference tool and enumerates the data returned, but it does not disclose additional behavioral traits such as default behavior when 'pair' is omitted or any rate limits/pagination. That extra context beyond annotations is minimal.

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 two sentences, front-loaded with the tool's purpose and data contents, followed by immediate usage guidance. Every word earns its place with no redundancy or filler.

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?

The tool is simple with two optional parameters and has an output schema, so return values are covered by structured data. However, the description does not specify how the 'pair' parameter affects results (all pairs vs one), nor does it explain the 'info' parameter values. The schema examples partially fill this, but the description alone is incomplete for a fully informed invocation.

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 0%, so the description must compensate. It fails to explain the 'info' and 'pair' parameters explicitly. The only hints come from the schema examples (e.g., info: 'leverage'), which are not part of the description. The description lists output fields but not input parameter meaning, leaving a significant gap.

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 it provides Kraken tradable pair info and lists specific data fields (base/quote, lot decimals, fee schedule, leverage limits, ordermin). It also distinguishes itself from sibling market data tools by positioning it as a directory to use before depth/ticker/ohlc calls.

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?

It directly instructs to 'Use as a directory before depth/ticker/ohlc calls', offering clear context for when to call it and naming the alternate tools for subsequent data. However, it does not explicitly cover when not to use it or other exclusions, so it falls just short of a 5.

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