Roo — set preview link

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

No annotations are provided, so the description carries the disclosure load. It clearly describes the special image behavior: a base64 data URI uploads a new image, while a previously-returned image_url retains the current image. It also names the Open Graph fields being modified. It could be even more transparent about what happens when image is omitted or what side effects may occur, but it covers the key functional behavior.

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 sentences, with the purpose first at social/chat and the one non-obvious behavior (image handling) explained while. There is no redundant filler and the structure is helpfully front-loaded.

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 focused update tool with a simple schema, the description together with the schema is largely complete: an agent can determine the target ID, required fields, and the optional image semantics. The main missing piece is whether omitting image preserves or clears the current image, and where the previously-returned image_url originates from.

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 input schema already documents 100% of the parameters, so the baseline is 3. The description adds a small amount of extra meaning by placing the fields in the Open Graph context and explaining the image upload/retention distinction, but it mostly restates what the schema already provides.

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 states a specific action and resource: controlling how a shortlink preview unfurls across social/chat via Open Graph title, description, and image. This is clearly distinguishable from the broader update_shortlink and other set_* siblings because it focuses specifically on preview metadata.

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 implies the tool should be used when the goal is to set or adjust a shortlink's social/chat preview appearance, but it never explicitly compares it to alternatives. It does not say things like 'use roo_update_shortlink for general fields' or 'this only changes preview metadata, not redirect behavior'.

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