YouTube Subtitles

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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds useful context — the third-party API dependency, JSON output, and a docs URL — but says nothing about missing/auto-generated captions, default language behavior when language_code is omitted, failure modes, or rate limits.

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?

Two tight sentences plus a docs link; the action and resource are front-loaded with no redundant restatement of the title. The docs URL is mildly extraneous but defensible as a pointer to deeper detail.

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?

With no output schema, the description should say more about the returned JSON structure (segments vs plain text, timestamps) and about the default-language behavior. It is adequate to invoke the tool but leaves meaningful gaps for interpreting results.

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 both parameters are already documented with examples, giving a baseline of 3. The description only reinforces language_code as the language selector and does not clarify what happens by default when it is omitted.

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?

States a specific verb and resource ('Fetch the subtitles of a YouTube video by video ID') plus the transport ('through the Decodo Web Scraping API') and the return shape (JSON). An agent can distinguish this from youtube_metadata or youtube_channel without opening any schema.

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?

Gives a clear use context ('read or summarise what is said in a video') and a parameter-level hint for language selection. It does not name alternatives or state when not to use it (e.g., when a video has no captions, or when metadata is what you actually need), so it stops short of explicit routing.

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