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

Annotations only declare the mutation/idempotency profile; the description adds genuinely new behavior: the link is single-use and expires in an hour, a human picks or records the file on the page, and it lands on the alarm on completion. It also discloses the return shape (page link plus direct send address), which annotations cannot convey.

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-loads the core action and keeps each sentence purposeful, but is somewhat dense with parenthetical clarifications and a slightly awkward colon-chained first sentence. Efficient overall, mild wordiness.

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?

With no output schema, the description still covers the return values, the interaction flow, the single-use/one-hour constraint, and the alternatives for files not on the device. Everything an agent needs to invoke and reason about the result is present.

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 100%, so both parameters are already documented, and the description's elaboration of the enum values (wallpaper as picture or short video, voiceover as a recorded voice message) largely duplicates the schema descriptions. Baseline 3 for high-coverage schemas.

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 and resource ('Makes a one-time lfg.gm page link for putting a file...on an alarm') and scopes exactly which alarm media slots it serves (wallpaper, song, voiceover). An agent can distinguish this from add_media_file and add_media_from_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?

Explicitly names the condition for this tool ('a file only on the person's own device') and the exclusion ('a file at a public link, or one this AI app has in hand, can go on directly'), which routes the agent to the sibling upload tools. Both when-to-use and when-not are stated.

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