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

With no annotations, the description carries the full burden and does so well: it discloses the blast radius of the mutation (every printed/shared copy redirects), that click history is preserved, that the destination is screened with Google Web Risk, and that a ShareCut API key on the Business plan is required. It still omits whether omitted fields are left untouched and what a rejected destination looks like, so not a 5.

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?

Front-loaded with the core action, and the QR-code rationale is placed right where it explains the value of updating rather than recreating. The 'stuck on a wall' phrasing is slightly decorative, but every sentence still carries a distinct fact (persistence, validation, auth).

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 mutation tool with no annotations and no output schema, the description covers side effects, auth requirements and validation adequately. It would be fully complete if it stated the partial-update semantics for optional fields and the failure mode when Web Risk blocks a destination.

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 the schema already documents all five parameters including the utm off-switch and accepted link formats. The description adds only a restatement of the mutable fields and the short-code immutability rule, which is a baseline-3 contribution.

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 (re-point/change) and resource (existing short link) plus the exact fields that can change, and contrasts implicitly with creation tools like shorten_url by saying the link already exists. An agent can distinguish it from delete_link, create_qr or shorten_url without opening a schema.

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?

Gives clear context for when to use it (making an already-printed QR code reusable) and draws the line at what it does not do (the short code itself never changes here). It never names a sibling tool explicitly, so the agent must infer that shorten_url handles new links, which keeps it short of a 5.

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