expand_link

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explains why ref:// tokens exist, that fetch_content can consume them directly, and that tokens must never be presented to users as URLs. It does not discuss failure modes for invalid or expired tokens, but the output schema likely covers the return shape.

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 compact and well-structured: it opens with the core purpose, adds necessary context about token substitution, gives a clear usage boundary, and ends with a parameter specification. No sentence is wasted.

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 single-parameter tool with an output schema, this description covers the purpose, when to use it, the parameter format, and the relationship to sibling tools. Nothing an agent needs to invoke it correctly is missing.

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 provides no description for the token parameter, so the description fully compensates. The Args section specifies that the token must be 'a ref://<id> token exactly as it appeared in search results' and notes that 'the bare id is also accepted,' adding format and provenance details the schema lacks.

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 starts with a specific verb and resource: 'Expand a shortened ref://<id> link token from search results back into the full URL.' It clearly distinguishes this tool from fetch_content by explaining that fetch_content accepts tokens directly, so an agent can tell when expand_link is the right choice.

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?

It explicitly states when to use the tool: 'only call this when you need the real URL, for example to show or cite a link to the user.' It also names the alternative behavior of fetch_content and warns against presenting ref:// tokens as URLs, giving both positive and negative usage guidance.

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