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

No annotations are provided, so the description carries the full burden. It does disclose one meaningful behavior, 'without redirecting', indicating a non-mutating lookup. However, it does not mention error behavior, auth requirements, or what happens for unknown slugs.

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?

A single, front-loaded sentence with no filler. Every word contributes to purpose or behavior, making it easy for an agent to parse quickly.

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 one required parameter, no nested objects, and an output schema, the description covers the essential context an agent needs. It is slightly thin only in not explicitly distinguishing itself from shortlink_status, but it is otherwise complete for a simple lookup tool.

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 100%, so the slug parameter is already fully documented. The description only restates that the slug is resolved and adds no format or syntax detail, matching the baseline for well-covered schema parameters.

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?

States a specific verb ('Look up'), a clear resource ('where a slug points'), and a behavioral boundary ('without redirecting'). This cleanly differentiates it from create_shortlink, delete_shortlink, and shortlink_status.

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 context is clear: use this when you need to know where a slug points rather than creating, deleting, or checking the status of a shortlink. It does not explicitly name alternatives, but the intended usage is evident.

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