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

No annotations, so the description carries the full burden. It does disclose an important behavioral trait — the link is ephemeral and expires after 24 hours — but says nothing about the write/mutation nature, permission or auth requirements, or rate limits. For a creation tool with zero annotation coverage, this is partial.

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 that states the action and the key constraint with zero waste. Nothing should be trimmed.

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?

An output schema exists, so return values need no explanation, and both params are fully covered by the schema. The description supplies the critical TTL constraint; only permissions/side-effect context is absent, which is a minor gap.

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%, so url and slug are already fully documented (including slug's auto-generation behavior). The description adds no parameter-level detail beyond the schema, so baseline 3 applies.

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+resource (create a short URL) and adds a meaningful qualifier — ephemeral, 24-hour expiry — that separates it from the durable-shortlink use case. It doesn't explicitly contrast with siblings, but the create verb is naturally distinct from delete/resolve/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?

No when-to-use or when-not-to-use guidance, and no mention of the alternative siblings (resolve_shortlink, shortlink_status) or conditions that should steer the agent here. The 24-hour expiry hints at a transient use case but this is left implicit.

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