Get token by id

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

With no annotations provided, the description carries the full burden, and it does well by indicating a read-only fetch operation and exact-match behavior. It doesn't disclose edge-case behavior like not-found handling or return format, but for a straightforward single-item getter this is a minor gap.

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 one tightly packed sentence with no filler. The core action and object are front-loaded, and every word adds clarity.

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 simple single-parameter getter, the description is sufficient to invoke the tool: the agent knows what to pass and what kind of result to expect. It omits return details and error behavior, but there is no output schema and the tool's simplicity lowers the burden.

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 coverage is 0%, but the description adds meaningful semantics to the sole 'id' parameter by labeling it a 'stable registry id' that must match exactly. This helps the agent understand the id's role beyond the raw schema pattern, though it doesn't elaborate on the allowed format beyond what the schema already provides.

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 ('Fetch') and a specific resource ('a single design token'), and clarifies the lookup mode ('by its exact stable registry id'). This distinguishes it from sibling tools like registry_list_tokens or registry_find_component without needing to inspect their schemas.

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 clearly implies the tool is for direct retrieval when the caller already knows the exact stable registry id, not for searching or listing. It doesn't explicitly name alternatives, but the 'exact stable registry id' precondition gives clear context for when to choose this tool.

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