Add URI download

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

With no annotations, the description carries the full burden. It usefully discloses that multiple URIs are accepted and that a GID is returned, but omits key behavior for a queueing tool: whether the download starts immediately or is merely registered, whether duplicate URIs/exit-on-error apply, and what happens to existing jobs.

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?

A single front-loaded sentence that names the action, its inputs, and its result with zero filler. Nothing needs trimming and nothing is buried.

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 mention of the returned GID compensates for the absence of an output schema, but with no annotations and no output schema the description should say more about async/blocking behavior and defaults for dir/out before an agent can call it confidently.

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 schema already documents dir, out, header and uris. The description only adds the cardinality note (one or more) and the protocol list, which is baseline-level value over structured fields.

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 specific verb (queue) plus resource (download URIs) and enumerates the supported protocols (HTTP, HTTPS, FTP, SFTP, magnet). It also names the primary side effect/return (new GID), so it is immediately distinguishable from sibling tools like aria2_list or aria2_remove.

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?

There is no when-to-use guidance, no mention of prerequisites, and no reference to alternatives (e.g., adding via torrent file or metalink). The agent must infer that this is the entry point for starting a download; nothing routes it explicitly.

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