get_info

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

With no annotations provided, the description carries the burden of behavioral disclosure. It transparently indicates this is a 'cheap probe' (low cost) and lists the exact data fields available. While it doesn't explicitly state read-only behavior or error handling, the 'probe' framing and metadata-only scope imply a safe, non-destructive operation.

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 two sentences, front-loading the core purpose and specific return fields, followed by a concise usage directive. Every word serves a purpose, with no filler or repeated schema information.

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?

Despite having no output schema or annotations, the description covers the tool's purpose, typical usage sequence, and the kind of data returned. It also references sibling tools implicitly by mentioning 'fetch a transcript', making the tool's role in the overall workflow clear. This is sufficient for a simple metadata probe.

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 a single 'url' parameter with no description, and schema coverage is 0%. The description compensates by clarifying that the tool probes 'a YouTube video', making it clear that the url refers to a YouTube video URL. This adds meaningful semantic context beyond the bare schema.

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's function: 'Cheap probe of a YouTube video' and enumerates specific data returned (title, duration, chapters, caption availability). This distinguishes it from sibling tools like get_transcript, which fetch transcripts rather than metadata.

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 directs usage: 'Call this first to decide whether to fetch a transcript and how to read it.' This provides clear context for when to use this tool versus alternatives, effectively positioning it as the preliminary step before transcript-related tools.

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