List allowlisted Lucky API prefixes

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

Annotations already indicate the tool is read-only, idempotent, and non-destructive, so the description's lack of additional behavioral detail is acceptable. It adds the useful relationship to lucky_api_call but does not disclose return format, ordering, or any other runtime behavior.

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 a single, efficient sentence that immediately states the resource and its relationship to lucky_api_call. There is no fluff or repetition of the title.

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?

For a zero-parameter listing tool with read-only annotations, the description is complete. It clearly says what will be listed and how it relates to the broader toolset. No output schema exists, but the expected content is unambiguous.

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 tool has zero parameters, earning the baseline of 4. The description does not need to explain parameter semantics, and the empty schema is fully consistent with the description.

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 ('Lucky API prefixes this MCP is willing to call'), clearly identifying the tool's purpose. It also implicitly differentiates itself from the sibling tool lucky_api_call by framing the catalog as the set of callable prefixes.

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: this tool lists what lucky_api_call is allowed to invoke. It does not explicitly state an exclusion or say 'use this before lucky_api_call', but the relationship is obvious enough that an agent can infer when it is relevant.

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