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

With no annotations provided, the description carries the full burden and does well: it discloses cursor pagination, output row shape equivalence, exact publishedAt behavior, the 2-credit cost, that empty results and failures are never charged, and cache semantics. This goes well beyond minimal disclosure, though it stops short of mentioning rate limits or auth requirements, which would be expected for full transparency.

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?

Three sentences with no filler: the first states the core function and row-shape guarantee, the second covers cost and failure policy, the third explains cache behavior. All information is relevant and front-loaded, with the most distinguishing detail (channel-videos row shape) placed early.

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?

The description covers pagination, cost, cache, failure policy, and output shape via a pointer to channel-videos. Since there is no output schema, the row-shape reference is helpful but assumes knowledge of the sibling tool's return fields. For a small-parameter list tool, this is nearly complete, though a couple of example output fields would fully close the gap.

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 adds context about cursor pagination and cost, but those are also reflected in the schema's parameter descriptions (cache, cursor). It does not add new parameter-level semantics beyond what the schema already provides, so the baseline holds.

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 identifies the resource ('Channel Shorts') and key capability (cursor pagination), and references 'same row shape as channel-videos' to hint at sibling differentiation. However, it lacks an explicit verb like 'List' or 'Fetch,' relying on the tool name and noun phrase to convey action. It is clear enough to distinguish from channel-videos, streams, and playlists, but not as explicit as it could be.

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 mention of 'same row shape as channel-videos' implies a relationship to that sibling tool, and 'Channel Shorts' signals when to use it, but the description never explicitly states 'use this for shorts, channel-videos for regular videos' or names exclusions. Usage context around pagination, credits, and caching is provided, so the agent gets some guidance but must infer the selection rule.

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