parse_youtube_url

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

With no annotations, the description carries the full burden and does so well: it discloses the input formats accepted and the fields extracted. It does not mention error handling for invalid or non-YouTube URLs, but for a parsing utility the given behavioral detail is substantial and not contradicted by any annotation.

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, information-dense sentences. The primary action and outputs are front-loaded, followed by a compact list of supported formats. No filler or repetition.

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?

For a simple one-parameter tool with no output schema, the description explains what to input and what will be returned. It leaves the timestamp unit unspecified and does not clarify whether all fields are always populated, but these are minor gaps for an extraction utility.

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 already documents the only parameter ('Any YouTube URL or video ID') with 100% coverage. The description repeats the same concept without adding format or constraint details, so the baseline of 3 is appropriate.

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 uses a specific verb ('parse') and resource ('YouTube URL'), and enumerates exactly what is extracted (video ID, channel ID, playlist ID, handle, timestamp). The supported URL formats are explicitly listed, which clearly distinguishes this utility from all sibling tools that deal with transcripts, metadata, or search.

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 makes the intended use obvious: when an agent has a YouTube URL or bare ID and needs structured identifiers. There are no explicit when-not-to-use statements or named alternatives, but no sibling tool performs this function, so the clear context is sufficient.

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