Shorten a URL

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

Annotations provide no safety hints (all false), so the description carries the full burden. It discloses important behaviors: anonymous links expire and aren't saved, and only total redirect counts are recorded without IPs, geolocation, device data, or referrers. This adds meaningful privacy context beyond the annotations.

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?

Three sentences, each earning its place: the first states the action, the second explains anonymous behavior, and the third gives usage guidance. No redundancy or filler.

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-link creation tool with no output schema and only one required parameter, the description covers purpose, usage, and privacy behavior. It is complete enough for an agent to invoke correctly without further clarification.

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 description coverage is 100%, with each parameter (url, slug, expiresInDays) already documented. The description adds no param-specific details beyond the schema, so the baseline of 3 is appropriate.

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 opens with 'Create a short link for a URL,' a specific verb and resource. It clearly distinguishes from the sibling tool 'shorten_links_bulk' by focusing on a single URL, and the usage line further clarifies its scope.

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?

Explicitly states when to use: 'Use when the user wants a short or shareable URL, or a link for a QR code.' It doesn't explicitly name alternatives or exclusions, but the singular 'a URL' implies the bulk sibling is for multiple URLs, so usage context is clear.

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