Skip to main content
Glama

Captapi

by io.github.CDCStream
OverviewDiscussionsAdmin

youtube_comments

Get comments on any YouTube video — text, author, likes, and truncated publishedTimeApprox from the relative label, with cursor pagination (nextCursor + hasMore). Flat 2 credits per call; 0 when the video has comments turned off (commentsDisabled: true). Costs 2 credits. Empty results and failures are never charged. Pass cache=true for a free 24h cache hit (default always fresh).

Input Schema

NameRequiredDescriptionDefault
urlYesPublic YouTube video URL, e.g. https://youtube.com/watch?v=ID. Not a TikTok/Instagram/Facebook URL. The URL platform must match this endpoint's platform. Do not pass cross-platform URLs, e.g. YouTube to TikTok, Instagram to Facebook, LinkedIn to X/Twitter, or Pinterest to Rumble.
cacheNoSet true to serve from the 24h response cache (0 credits on hit). Default false — always fetch fresh.
limitNoMax items to return (default 50, max 500). Flat 2 credits per call.
cursorNoPagination cursor. Leave empty for the first page; then pass the nextCursor value returned in the previous response.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • changedInput schema / properties / cache / description
      Previous value: -"Set true to serve from the 24h response cache (0 credits on hit). Default false — always fetch fresh. Envelope includes cached + cachedAt on hits."New value: +"Set true to serve from the 24h response cache (0 credits on hit). Default false — always fetch fresh."
  2. Changed3 schema fields changed
    • changedInput schema / properties / cache / description
      Previous value: -"Set true to serve from the 24h response cache. Default false — always fetch fresh data."New value: +"Set true to serve from the 24h response cache (0 credits on hit). Default false — always fetch fresh. Envelope includes cached + cachedAt on hits."
    • changedInput schema / properties / limit / description
      Previous value: -"Max items to return. Default 50, max 500. Billed per result."New value: +"Max items to return (default 50, max 500). Flat 2 credits per call."
    • changedInput schema / properties / url / description
      Previous value: -"Public YouTube video URL, e.g. https://youtube.com/watch?v=ID. Not a TikTok/Instagram/Facebook URL. The URL platform must match this tool's platform. Do not pass cross-platform URLs, e.g. YouTube to TikTok, Instagram to Facebook, LinkedIn to X/Twitter, or Pinterest to Rumble."New value: +"Public YouTube video URL, e.g. https://youtube.com/watch?v=ID. Not a TikTok/Instagram/Facebook URL. The URL platform must match this endpoint's platform. Do not pass cross-platform URLs, e.g. YouTube to TikTok, Instagram to Facebook, LinkedIn to X/Twitter, or Pinterest to Rumble."
  3. Changed1 schema field changed
    • addedInput schema / properties / cursor
      Added value: +{
+  "description": "Pagination cursor. Leave empty for the first page; then pass the nextCursor value returned in the previous response.",
+  "type": "string"
+}
  4. Changed1 schema field changed
    • changedInput schema / properties / cache / description
      Previous value: -"Responses are cached for 24 hours by default. Set false to bypass the cache and always fetch fresh data (default true)."New value: +"Set true to serve from the 24h response cache. Default false — always fetch fresh data."
  5. Changed1 schema field changed
    • addedInput schema / properties / cache
      Added value: +{
+  "description": "Responses are cached for 24 hours by default. Set false to bypass the cache and always fetch fresh data (default true).",
+  "type": "boolean"
+}
  6. Changed1 schema field changed
    • changedInput schema / properties / url / description
      Previous value: -"Public YouTube video URL, e.g. https://youtube.com/watch?v=ID."New value: +"Public YouTube video URL, e.g. https://youtube.com/watch?v=ID. Not a TikTok/Instagram/Facebook URL. The URL platform must match this tool's platform. Do not pass cross-platform URLs, e.g. YouTube to TikTok, Instagram to Facebook, LinkedIn to X/Twitter, or Pinterest to Rumble."
  7. First observed

TDQS

A3.8/5.0
Behavior4/5

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

With no annotations, the description carries the full burden and does a solid job: it discloses the exact credit cost (flat 2, free on cache hit, free on empty results/failures, 0 when commentsDisabled), the 24h cache TTL, and pagination semantics (nextCursor + hasMore). It omits auth/permission requirements and rate limits, but the pricing and pagination disclosure is substantive.

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

Conciseness4/5

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

Front-loaded with the returned fields, then pagination, then cost. It is slightly padded by restating the price twice ('Flat 2 credits per call' then a standalone 'Costs 2 credits') and repeating the cache behavior already in the schema, but otherwise every sentence earns its place.

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

Completeness4/5

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

There is no output schema or annotations, so the description must compensate, and it largely does by naming the return fields, the pagination contract, and the billing edge cases. The lack of any auth/permission note and only partial output structure keep it short of complete.

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%, so the baseline is 3; the description goes slightly beyond by tying cursor pagination to the returned nextCursor/hasMore and by explaining that the 2-credit cost and the zero-cost commentsDisabled case apply per call. It adds real meaning about cost implications not present in the schema.

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

Purpose4/5

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

States a specific verb and resource ('Get comments on any YouTube video') and enumerates the returned fields (text, author, likes, publishedTimeApprox), so the agent knows exactly what it fetches. It does not, however, distinguish itself from close siblings such as youtube_comment_replies or youtube_shorts_comments, leaving that differentiation to the reader.

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

Usage Guidelines3/5

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

Usage guidance is limited to parameter behavior ('Pass cache=true for a free 24h cache hit') rather than tool selection. There is no statement of when to choose this over youtube_comment_replies or youtube_shorts_comments for related content, so context is only implied by the name.

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

All Captapi toolsInspect
Try in Browser
One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources