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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered structurally. The description reinforces this usefully with "Nothing is created by this tool," which is meaningful for a tool that hands back a link someone might assume registers something. It does not, however, say that the returned artifact is a URL, whether it expires, or whether sign-in is needed to use the link.

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?

Two short sentences, front-loaded with the action and resource, with zero filler. The parenthetical Grandma example duplicates the watcher schema description, a small redundancy, but nothing is wasted overall.

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 zero-required-parameter, no-output-schema link builder, the description is nearly sufficient: it conveys the output's nature (a link), the target app, and the absence of side effects. The remaining gap is that it never explicitly states the return value or how the optional watcher alters the resulting link.

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 coverage is 50%: watcher is documented in the schema and the description restates it almost verbatim ("optionally naming who will watch it (for example Grandma)"), while occasion is only implied by "for an occasion" although its enum is self-explanatory. The description confirms both parameters are optional but adds no meaning beyond the schema.

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 ("Build a link") and a precise resource ("the free Wisheroo video wish list recorder for an occasion"). The resource naming implicitly separates it from the sibling start_song_link, but there is no explicit pointer to that sibling.

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?

The context of use is implied (you want a wish-list recording link for a given occasion), but there is no explicit when-to-use vs. when-not guidance and no reference to alternatives like start_song_link or about_wisheroo. The "Nothing is created" line is the only disambiguating signal.

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