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

Annotations only cover the safety profile (readOnly, non-destructive, non-idempotent), and the description adds genuinely important behavior the agent could not otherwise know: the page is single-use, expires after 30 minutes, lives on the external domain lookunique.eu, and routes the uploaded photo back into this conversation. One-time use and the 30-minute window are exactly the constraints an agent must communicate to a user.

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 tight sentences with no filler, and the single most important fact – one-time page, 30-minute validity – is front-loaded. The second sentence adds the ownership/scoping link to the conversation without redundancy.

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-parameter tool with annotations and no output schema, the description covers the essentials an agent needs: durability (one-time, 30 minutes), where the upload happens, and where the artifact ends up. The one remaining gap is that it never explicitly says the return value is a link the agent should hand to the user, which is left to the tool name.

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?

The tool takes no parameters, so there is nothing to document and the baseline is 4. The description correctly adds no parameter-level claims and does not invent any inputs.

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 makes clear this tool stands up a one-time external page where a person drops a photo, and that the resulting drawing is tied to this conversation – which distinguishes it from draw_from_photo and check_drawing. The verb ('creates/produces a link') is implied rather than stated, so the agent must infer that the tool's output is a shareable URL.

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 description explains the mechanism but never says when to reach for this tool versus siblings such as draw_from_photo or order_link. There is no condition, prerequisite, or exclusion; the agent must infer the usage scenario from the phrase 'the person can drop a photo'.

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