Check YouTube access

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds genuinely new behavioral context: it probes live network paths from this machine and reports timings, which tells the agent this is a real-time environment check rather than a cached lookup.

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 sentences, zero filler. The scope enumeration is front-loaded and the usage trigger is the closing sentence, which is exactly the right ordering for a diagnostic tool.

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 no-param diagnostic with no output schema, the description covers what is checked and when to invoke it. It only lightly gestures at the return shape ("with timings") without saying what a partial or total failure report looks like, a small gap given there is no output schema to fill it.

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 tool takes zero parameters, so the baseline is 4. The description correctly adds nothing about parameters, and no parameter meaning is left ambiguous.

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?

Specific verb ("Check") plus an enumerated scope: search, video details, transcripts, watch page, channels, yt-dlp, ffmpeg. It is unmistakably a diagnostic tool, cleanly distinguishable from youtube_search, youtube_fetch, and youtube_channel.

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 an explicit trigger condition: "Run it when other youtube_* tools fail," which names the sibling tools it complements. It stops short of stating when not to run it (e.g. before any failure, or as a routine preflight), so it is clear context without full exclusions.

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