add_external_dll

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

Description adds context beyond annotations: it explains the download-then-copy process ('The Node MCP server downloads the URL to a temp file and asks the Unity Editor to copy it into the Assets tree and refresh the AssetDatabase'). Annotations already mark it as non-readOnly and non-destructive, so the description provides useful procedural detail.

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?

Description is concise (4 sentences) and front-loaded: first sentence states purpose, second gives use cases, third explains process, fourth contrasts with sibling. No wasted words.

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?

Given no output schema, description still covers essential behavior: where file goes, how it's handled, and the overwrite flag. It mentions AssetDatabase refresh. Could briefly address error handling (e.g., URL failure) but overall sufficient for a simple file operation.

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?

Input schema has 100% coverage with descriptions for all 4 parameters. The description adds value for 'fileName' by explaining it defaults to the last URL segment, but for other parameters it largely repeats schema info (e.g., 'overwrite' description is same). Baseline 3 is appropriate since schema already does heavy lifting.

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 clearly states the tool downloads a raw DLL or binary asset from a URL and installs it under Assets/<destinationFolder>/<fileName>. It specifies the verb (downloads/installs) and resource (DLL/binary asset), and distinguishes it from sibling tools like add_package by mentioning it is for assets not published as Unity packages.

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 provides when to use this tool: for native plugins, NuGet DLLs, CDN-hosted libraries. It also gives examples (zxing.unity.dll, Newtonsoft.Json.dll) and tells when NOT to use it by suggesting add_package for git-hosted UPM packages.

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