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

Annotations already declare the write/destructive/non-idempotent/open-world profile, so the bar is lower. The description adds real value by stating the link and QR are permanent, that an update with qr_id preserves the existing short link and QR code while swapping the destination, and that it doubles as a form finalizer — though it never says what an update overwrites or whether operations are reversible.

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, front-loaded with the primary action, then the fallback routing, then the update semantics. No filler or repeated schema content.

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 6-parameter mutation with full schema coverage, full annotations, and an output schema, the description covers selection, routing, and update semantics. Nothing an agent needs to pick and call this tool 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 coverage is 100% so the baseline is 3, but the description goes beyond the schema by explaining the qr_id branch (update existing QR, preserving link) and framing file_url as an already-hosted public URL. It does not clarify asset_iri or original_filename beyond the schema text.

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?

Specific verb (create or update) plus resource (permanent short link and dynamic QR code) plus input constraint (file already hosted at a public URL). It clearly separates itself from siblings like host_file and save_short_link by scoping to already-hosted files.

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 states when to use it (fallback when the host cannot pass an attached file, finalizer for the in-chat upload form) and names the preferred alternative (host_file) with the condition that selects it. The qr_id branch defines update vs create behavior.

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