youtube_search_channels

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

Annotations already mark the operation as read-only, idempotent, and non-destructive. The description adds valuable context beyond annotations: it explicitly requires YOUTUBE_API_KEY and discloses the output fields (subscriber counts, video counts, country). This is meaningful supplementary transparency, though it does not cover rate limits or error handling.

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-loaded with the action, and every clause adds value. No wasted words or redundancy with the schema/annotations.

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 tool has 5 parameters and no output schema, but annotations are rich. The description covers the primary purpose, key return fields, and an API requirement, which is adequate. However, it omits details about query formatting, filter interaction, or pagination behavior—though some of this lives in the schema. Not a fully comprehensive picture but above average.

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 coverage is 100%, so all parameters are documented. The description does not add extra semantic detail beyond the schema; it only paraphrases the query field as 'name/topic.' This aligns with the baseline 3 for high schema coverage.

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 searches YouTube channels by name or topic, with a specific verb ('Search') and resource ('YouTube channels'). It also lists returned fields (subscriber counts, video counts, country), which distinguishes it from sibling tools like youtube_get_channel_info and youtube_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 implies usage for channel discovery but does not explicitly compare itself to alternatives like youtube_search (likely videos) or youtube_get_channel_info. The API key requirement is a useful prerequisite, but without exclusions or named alternatives, the guidance is only implied.

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