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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses one key behavior — that no browser is launched — and implies the output is a URL, but it does not state whether the tool makes network calls, how instances are chosen, whether the video_id is validated, failure behavior, or the return format.

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 a single efficient sentence with no wasted words, and it front-loads the core purpose and key behavioral caveat. It is appropriately sized for a simple tool, though it sacrifices informative content for brevity.

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 5 parameters, no output schema, and no annotations, this description is incomplete. An agent still lacks definitions for parameters like listen and sponsorblock, does not know what structure the returned URL takes, and cannot predict side effects — all of which the description should supply given the absence of structured context.

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 0%, so the description must compensate for the 5 parameters, but it adds nothing about listen, quality, autoplay, sponsorblock, or video_id beyond what the bare names suggest. The output framing ('browser-ready URL') weakly implies the parameters configure the generated URL, which is some value, but well short of adequate compensation.

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 uses a specific verb ('Generate') and resource ('Piped or Invidious URL'), making the tool's output clear. It implicitly differentiates from siblings by describing a URL-generation function rather than search or metadata retrieval, though it never names the siblings explicitly.

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?

No guidance is given on when to choose this tool over youtube_search or youtube_video, and no alternatives or exclusions are mentioned. The phrase 'without launching a browser' hints at a programmatic use case, but the conditions that would select this tool are left entirely to inference.

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

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does disclose that the tool routes through Piped with an Invidious fallback, which is a behavioral trait. However, it does not specify return format, pagination, rate limits, or auth requirements, leaving the agent under-informed about consequences.

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 a single sentence with no filler or repetition. It front-loads the core purpose and adds a small amount of backend detail, making it highly concise.

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 that there is no output schema and no annotations, the description is too sparse to be complete. It explains the tool's purpose but leaves the agent without guidance on how to use the filter enum, what the limit controls, or what the result format will be. For a tool with three parameters, more context is needed.

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?

The input schema defines three parameters (query, filter, limit) but the description provides no additional meaning for any of them. The verb 'search' implies the query parameter, but filter and limit semantics remain entirely unspecified. With 0% schema description coverage, the description fails to compensate.

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 clear action 'Search' on the resource 'YouTube' and names the backend services (Piped with Invidious fallback). This distinguishes it from sibling tools youtube_video and youtube_play, which are about single videos or playback. The agent can easily tell this is the search tool.

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 gives an implied use case (searching YouTube) but does not explicitly state when to prefer this tool over youtube_video or youtube_play, nor does it mention any exclusions or alternatives. It lacks the explicit routing found in high-quality definitions.

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

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

No annotations are provided, so the description carries full disclosure responsibility. It does reveal that the tool uses Piped and may fall back to Invidious, which is useful, but it does not mention failure behavior, external network effects, or the shape of the returned data. 'Retrieve' implies read-only, yet that safety trait is not explicitly confirmed.

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 a single, tightly written sentence that front-loads the action and adds a meaningful fallback detail. There is no redundancy or filler, making it appropriately concise for a one-parameter tool.

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 tool has no annotations and no output schema, so the description needs to explain more: what metadata fields are returned, what stream variants are provided, and what happens if Piped or Invidious fails. Without this, an agent can invoke it but cannot predict the response or handle common failures.

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?

The schema contains only video_id with a type and pattern, and the description adds no parameter-level explanation. With 0% schema description coverage, the description should have clarified that video_id is a YouTube video ID rather than a URL and explained any format expectations beyond the regex.

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 uses a clear retrieval verb and identifies the resource as 'video metadata and streams,' which separates it from youtube_search and youtube_play. It does not explicitly mention that the target is identified by video_id, and 'streams' could be more specific, but the core purpose is understandable.

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?

Usage context is implied by the verb and resource: use this when you need metadata or streams for a specific video. However, there is no explicit guidance about when not to use it or how it relates to youtube_search and youtube_play, so the agent must infer the distinction.

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