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

Annotations already declare this is a safe read (readOnlyHint=true, destructiveHint=false, closed-world), so the bar is lower. The description adds genuinely useful behavior beyond that: download_url is signed, is null when not exported, and requires a prior export step, which an agent would otherwise not know.

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 short sentences, front-loaded with the core action and then the conditional download_url caveat. No filler and every sentence carries information.

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?

With no output schema, the description carries the burden of explaining returns, and it covers the key output fields (download_url, export_status) and the condition connecting them. Nothing an agent needs to call it correctly or interpret the response 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 short_id parameter is already documented, including its source ('from list_shorts or get_clip_status'). The description adds no further meaning about the parameter, so baseline 3 applies.

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 verb and resource ('Get one short by id'), clearly distinguishing it from list_shorts, and adds scope by noting it covers both app-made shorts and clip_video results. It does not explicitly contrast itself against the nearest sibling, but the singular-vs-list distinction is obvious.

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?

It explains a clear usage condition: download_url is null while export_status is not_exported, and the user must export in the SendShort editor first. It doesn't explicitly name an alternative tool, but the prerequisite workflow is spelled out.

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