YouTube Video Summarizer (pay-per-call)

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

No annotations provided, so description carries full burden. It discloses pricing (pay-per-call via x402), no account needed, and error behavior (no charge on failure). It does not mention rate limits but provides important 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.

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

Three sentences, each adding value: purpose and SKU, pricing and account info, error handling. No redundancy, front-loaded with key action.

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 and two simple parameters, the description covers core aspects: what it does, pricing, error condition. It could explicitly state return type but 'raw transcript text' is sufficient.

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 coverage is 0%, so description must compensate. It adds BCP-47 format for the 'language' parameter and default value 'en', but does not describe the 'url' parameter format. This provides some addition beyond schema but leaves a gap.

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 fetches raw transcript text of a YouTube video. It distinguishes itself from siblings like 'summarize_youtube_video' by noting it uses a cheaper SKU without a model run, and from 'list_new_channel_videos' by focusing on transcripts.

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 explains when to use this tool (fetching transcript, cheaper option) and includes error handling (no captions returns error, not charged). However, it does not explicitly contrast with the sibling tools, though the context is clear.

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?

With no annotations, the description bears full burden and delivers: states statelessness, no authentication needed, payment via USDC, error handling (unresolvable channel or naive timestamp returns error without charge), and return format (new video ids/titles/times, cursor for next poll). All behavioral traits are disclosed.

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 concise (single paragraph) and front-loaded with purpose. Every sentence adds value: purpose, statelessness, parameter details, return format, payment, error handling. No fluff or redundancies.

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, no annotations, and 3 parameters, the description covers all necessary aspects: tool function, parameters, return value, cursor mechanism, payment, and error behavior. It is fully self-contained for correct invocation.

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 coverage is 0%, so description must compensate fully. It explains channel parameter accepts URL/@handle/id, since is ISO 8601 timestamp, since_video_id is video ID, and both are optional. It also explains the return value includes newest_video_id as the next cursor, linking parameters to usage.

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 returns new videos on a YouTube channel since last poll, using a specific verb 'list' and resource 'new_channel_videos'. It distinguishes from siblings (get_youtube_transcript, summarize_youtube_video) by focusing on monitoring rather than content extraction.

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 explicitly explains when to use the tool (for stateless channel monitoring), how to use it (pass channel identifier and optional cursor), and provides context such as pay-per-call model and error handling. It implies when not to use (if you need accounts/webhooks) and mentions the x402 payment mechanism.

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?

With no annotations provided, the description carries full burden. It discloses pay-per-call via x402 (USDC), no account/API key needed, error handling (no charge for failures), and language support. It covers safety and cost behavior well.

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 concise with no wasted words. It front-loads the primary action and then adds critical context (cost, error handling, language). Every sentence earns its place.

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 two parameters, no output schema, and no annotations, the description covers purpose, cost, error behavior, and language support. It is sufficiently complete for an agent to use the tool effectively, though exact output format (e.g., plain text vs structured) is not specified.

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. It explains the language parameter as BCP-47 supporting 100+ languages and implies the URL parameter must be valid. This adds meaning beyond the schema's property definitions.

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 summarizes a YouTube video and returns the summary text. It distinguishes itself from siblings like get_youtube_transcript (which returns raw transcript) and list_new_channel_videos (which lists videos), making the purpose unambiguous.

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 explains when to use the tool (to get a summary), the pay-per-call cost model, and that a bad URL or missing captions returns an error without charge. While it doesn't explicitly mention alternatives, the context is clear enough for an agent to decide.

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