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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the description's main job is to add context. It does that by disclosing the 15-minute expiry, which is a real behavioral constraint an agent must account for. It leaves unstated whether links are single-use or bound to any session, which is the remaining gap.

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: the first defines the action and its expiry, the second supplies the parameter sourcing. Nothing is redundant and the most decision-relevant fact (short-lived) 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?

For a two-parameter, non-destructive read tool with no output schema, the description supplies the essentials: what is produced (a download link), how long it lives, and where the id comes from. Minor omissions like link reuse semantics are acceptable at this complexity.

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 only 50% — 'upload_id' has no schema description — and the description compensates by explaining that the value originates from record data returned by query_records. That is genuine meaning beyond the schema. The 'site' parameter is already documented in the schema, so nothing extra is needed there.

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 concrete verb+resource pair ('Create a short-lived download link ... for a file a visitor uploaded through a form') plus the lifetime of the link. This is clearly distinguished from siblings like get_topup_link or upload_asset, which serve different link/file purposes.

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?

Gives an explicit prerequisite chain: the upload_id must come from record data returned by query_records, which tells the agent when and how the tool becomes callable. It does not state exclusion conditions (e.g. what to do if the upload expired), so it stops short of full when/when-not guidance.

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