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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds value by disclosing that the result is cached for the MCP process lifetime and specifying the return structure, which goes beyond what annotations provide.

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 concise, with front-loaded purpose and usage instruction. Every sentence adds value: first sentence states purpose, second provides usage guidance, and the return format block is helpful without being excessive.

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 zero parameters, no output schema (but description provides return format), and comprehensive annotations, the description fully equips the agent with necessary context: when to call, what it returns, caching behavior, and relationship to other tools.

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 zero parameters, so schema coverage is 100%. With no parameters, the baseline score is 4. The description does not need to add parameter information but does provide return format details, which is appropriate.

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 uses a specific verb ('List') and resource ('jurisdictions (countries/states)') and clearly states the tool's role in the legal corpus context. It differentiates from sibling list tools by focusing on jurisdictions and their ISO codes.

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?

Explicitly instructs the agent to call this tool FIRST when answering legal questions to obtain valid ISO codes for other tools, providing clear when-to-use guidance. Also mentions caching behavior, which adds to usage context.

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