downloadstream

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

With no annotations provided, the description carries full burden for behavioral disclosure. It usefully mentions quota cost (1 unit) which is valuable operational context. However, it doesn't describe what 'stream or download info' actually returns (formats, data structure, whether it's actual media or metadata), rate limits beyond quota, or error conditions like the 403 mentioned in the schema. It adds some value but leaves critical behavioral aspects unspecified.

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?

The description is extremely concise (two brief sentences) with zero wasted words. It's front-loaded with the core function and follows with important quota information. However, the extreme brevity comes at the cost of clarity and completeness, which is reflected in other dimension scores.

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 tool with 3 parameters, no annotations, and no output schema, the description is inadequate. It doesn't explain what the tool actually returns (streaming links? download URLs? metadata?), doesn't differentiate it from similar sibling tools, and provides minimal behavioral context beyond quota cost. Given the complexity of YouTube content access and the rich sibling tool ecosystem, this description leaves too many questions unanswered.

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 fully documents all three parameters (id, cgeo, lang). The description adds no additional parameter semantics beyond what's in the schema. The baseline score of 3 is appropriate when the schema does all the parameter documentation work.

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 'Stream or download info' is vague and tautological with the tool name 'downloadstream'. It doesn't specify what type of content is being streamed/downloaded (YouTube videos/shorts) or what 'info' refers to. While the input schema reveals this is for YouTube content, the description itself lacks the specific verb+resource clarity needed for independent understanding.

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?

The description provides no guidance on when to use this tool versus the many sibling tools available (like video_details, shorts_details, channel_videos, etc.). It mentions quota cost but doesn't explain why one would choose this tool over alternatives for similar YouTube content access. No explicit when/when-not or alternative tool references are provided.

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