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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the description needs to explain *why* this edit is destructive — e.g. that changing the destination silently breaks printed QR codes, existing shares, or click history, and that the change is immediate. None of that context is provided; the description merely restates the mutation already visible in 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?

A single front-loaded sentence with no filler, so an agent gets the gist immediately. It is arguably too terse rather than padded, which costs it nothing on this dimension.

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 3-parameter mutation tool with no output schema, the definition is minimally adequate: the schema covers the parameters and the annotations cover the safety profile. It is missing the one thing the structured data cannot convey — the real-world consequence of repointing a shortlink and what the response confirms.

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%, and the schema already explains that omitting url or description keeps the current value, so the baseline is 3. The description adds nothing beyond naming the two optional fields, but it does not contradict or omit anything either.

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 gives a specific verb ('Update') and resource ('shortlink') plus the two mutable fields (destination URL, description), which cleanly separates it from create_shortlink, delete_link, and update_alias. It stops short of naming any sibling, but the resource+field framing is enough to identify the tool.

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?

Usage is only implied: an agent can infer this is the tool for changing a link's target or label, but there is no explicit statement of when to prefer it over update_alias, bulk_create_links, or delete/create. No prerequisites (ownership, existing shortlink) or exclusions are given.

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