Server Quality Checklist

Tool Scores

• youtube_video_factsA
  4.5/5.0
  Behavior4/5

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

  With no annotations provided, the description carries the full burden. It discloses that the tool is cheaper than transcript retrieval, the exact data it returns, and that it does not read captions in the first sentence. It does not cover edge cases like unavailable videos, but for a simple read-only lookup, the transparency is solid.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is compact and front-loaded with the primary purpose. Every sentence adds value: the first sentence defines the action, the second enumerates return fields, and the third gives usage context. There is no redundancy or filler.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple one-parameter metadata lookup tool with an output schema, the description is complete. It covers what the tool does, what data it returns, and when to use it relative to sibling tools. The presence of an output schema means return format details need not be repeated here.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The schema already provides a complete description for the single 'url' parameter (100% coverage). The description does not add extra meaning about the parameter beyond what the schema states, but it is not lacking since the schema is sufficient.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool looks up YouTube video metadata without reading captions. It lists specific data fields (title, channel, duration, publish date, counts, etc.) and differentiates from the sibling youtube_transcript by framing it as a metadata lookup rather than a transcript fetch.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  Explicit guidance is given: use this tool when the question is about the video itself, not its contents, and to check for captions before requesting a transcript. It also mentions the cost advantage over pulling a transcript, effectively saying when to prefer this tool over youtube_transcript.

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

• youtube_playlistA
  4.7/5.0
  Behavior4/5

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

  With no annotations, the description carries full burden. It discloses what the tool returns (watch URLs and playlist title) and what it does not (video details), plus an edge case about watch links. While it doesn't explicitly state read-only semantics or error behavior, the verb 'List' and the outlined scope provide sufficient transparency for a simple operation.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is three sentences, each with a distinct purpose: statement of core functionality, clarification of output scope, and usage guidance with an edge case. No redundant information, and the primary purpose is front-loaded.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a single-parameter tool with an output schema, the description covers all necessary aspects: what it returns, what it excludes, how to use it in a workflow, and an edge case. The mention of sibling tools completes the integration picture, making it self-sufficient for an AI agent.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The schema description for the single parameter is complete ('A youtube.com or youtu.be link'), but the tool description adds meaningful nuance: it clarifies that a watch link embedded in a playlist is also accepted. This goes beyond the schema and enriches the parameter semantics.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool lists videos in a YouTube playlist in playlist order. It distinguishes itself from siblings by explicitly noting it returns only watch URLs and the playlist title, not video details, and directs users to call youtube_video_facts or youtube_transcript for that.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description gives explicit usage guidance: use it to unpack a playlist, then call the sibling tools on the returned URLs. It also covers an edge case (watch links inside playlists), providing clear context on when and how to use the tool.

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

• youtube_transcriptA
  4.9/5.0
  Behavior5/5

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

  With no annotations, the description fully discloses behavior: default returns whole transcript, window edges return whole caption lines, language fallback order, presence of language and auto_generated fields, absence of timestamps, and the Shorts limitation. This is rich, actionable behavioral context.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is well structured with a clear lead sentence followed by logically grouped details. Every sentence adds value—parameters, language behavior, output characteristics, and a pointer to an alternative—without unnecessary fluff.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a tool with 3 parameters, an output schema, and no annotations, the description covers all critical aspects: input URL format, parameter semantics, edge cases, language handling, output limitations, and unsupported cases. It is fully complete for an agent to select and invoke correctly.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema coverage is 100%, but the description adds semantic nuance beyond schema: it clarifies that start_seconds/end_seconds narrow the response, that 'the whole thing' is returned by default, and that caption lines straddling the window are returned whole. This goes beyond the schema's terse descriptions.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description opens with a clear, specific verb and resource: 'Read what is said in a YouTube video, as plain text.' It also differentiates from siblings by explicitly naming youtube_video_facts for metadata-only needs, making the tool's scope unmistakable.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  It provides explicit usage guidance: use start_seconds/end_seconds for long videos to keep responses small, warns that Shorts are unsupported, and directs users to youtube_video_facts when they only need title/length/view count. This covers when, when-not, and alternatives.

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