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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the description doesn't need to restate those. It adds valuable behavioral context: providing qr_id updates the file destination while preserving the existing short link and QR code, and the tool both creates and updates. This goes beyond what the annotations alone 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?

Three sentences, each earning its place: the core action, the when-to-use and alternative, and the update behavior plus upload-form context. The most important scoping information is 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?

The description is complete for a tool with an output schema and 100% schema description coverage. It covers creation vs update, the fallback scenario, the alternative to prefer, and the upload-form integration. Nothing an agent needs to select and invoke it correctly is missing.

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 baseline is 3. The description adds meaning beyond the schema by mapping 'file or PDF' to typology and explaining that qr_id triggers an update that preserves the existing short link and QR code. This enriches the semantics of key parameters without needing to repeat all schema details.

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 uses a specific verb and resource: 'Create or update a permanent short link and dynamic QR code for a file or PDF that is already hosted at a public URL.' It clearly differentiates from siblings by naming host_file as the preferred alternative for local attachments and by describing the update path via qr_id.

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?

Explicit usage guidance is provided: 'Use this as a fallback when the host cannot pass an attached file; prefer host_file for local or host-native attachments.' It also specifies when to update vs create, and notes its role as the finalizer step in the in-chat upload form.

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