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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does describe the output (summary, auth, dataset size, tool list) but does not explicitly state whether the operation is read-only, whether authentication is required to call this endpoint, or any side effects. The description is not misleading, but it leaves these behavioral traits implied rather than explicit. Given the lack of annotations, this is a moderate gap, so a 3 is warranted.

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 concise sentences, with the primary purpose front-loaded in the first sentence. The English version is efficient, and the Chinese translation adds no redundancy. Every element contributes to understanding the tool's function and return value. No filler or unnecessary detail is present.

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 has no parameters, no output schema, and no annotations, the description must convey what the tool returns. It does so by listing the four components of the metadata. It does not mention format or details of the response, but for a metadata endpoint this is adequate. An agent can decide when to call it and what to expect. The description is complete enough for the tool's simplicity.

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 is empty with zero parameters, so schema coverage is 100% by default. The rubric sets a baseline of 4 for tools with 0 parameters. The description does not need to add parameter semantics because there are none. It does not introduce any confusion, and the baseline applies. A score of 4 reflects that the description fully satisfies the parameter dimension for a parameterless tool.

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 states a specific verb ('Get'), a clear resource ('service meta'), and enumerates the exact contents (summary, auth, dataset size, tool list). It is unambiguous and clearly distinct from sibling tools that focus on haplogroup data retrieval, so an agent can immediately understand what this tool does and why it differs.

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?

While the description does not explicitly state 'use this for service metadata and not for haplogroup queries', the purpose is so distinct that context makes the usage clear. There are no exclusions or alternatives mentioned, but the separation from siblings is strong enough that an agent would not confuse it. This qualifies as clear context with no explicit exclusions, so a 4 is appropriate.

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