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

With no annotations, the description carries the behavioral disclosure burden. It provides useful transparency about credit costs, zero-credit behavior when hasLiveTab is false, empty/failure charging, and cache semantics. Some cost and cache details repeat what is already in the schema, but the added 'empty results and failures are never charged' policy and the Live-tab-only scope are genuinely valuable beyond the structured fields.

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 three tight sentences that front-load scope first ('Channel Live tab only') and then efficiently cover cost, failure charging, and cache behavior. There is no filler, and every clause contributes decision-relevant 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?

For a relatively simple 3-parameter tool with no output schema, the description plus the schema cover the essential selection and invocation context: which channel tab is read, accepted URL formats, limit behavior, cache behavior, and charge implications. The main gap is that the return shape is only hinted at via 'liveStatus per row', but this is minor given the otherwise rich parameter documentation.

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 the baseline is 3. The description mostly restates cache and credit behavior already present in the cache and limit parameter descriptions, and it adds no new meaning for the url parameter. The schema itself already documents URL formats, platform-matching constraints, default/max limit values, and credit conditions.

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 name youtube_channel_streams combined with 'Channel Live tab only — liveStatus per row' tells an agent that the tool targets a YouTube channel's Live tab and returns per-row live status. It lacks an explicit verb like 'retrieve' or 'list', but it is specific enough to distinguish the tool from sibling endpoints such as youtube_channel_videos, youtube_channel_shorts, and youtube_channel_playlists.

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 implies usage context through 'Channel Live tab only' and the cache/cost behavior, but it never explicitly says 'use this when you need live streams' or names alternatives. An agent has to infer when to pick this over related sibling tools like youtube_channel_videos or youtube_channel_playlists, so usage guidance is only partially explicit.

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