Edit channel profile

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

Beyond the supplied annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=true), it discloses that the edited fields are publicly visible, that a user confirmation step is required first, and that only supplied fields mutate. That is meaningful operational context the annotations do not convey, though the two-step confirmation/token choreography is only implied rather than spelled out.

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 tight sentences, front-loaded with the editable fields, then the partial-update rule, then the safety/confirmation note, ending with a parenthetical exclusion. Every sentence carries information; only minor compression is possible.

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 an 8-parameter mutation with a nested object and no output schema, the definition covers scope, mutation semantics, public visibility and the confirmation requirement. The one gap is that localization merging (per-language title/description merged with existing entries) is documented only inside the schema rather than surfaced in the description.

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 88%, so the schema already documents channel, country, keywords, localizations, default_language, confirmation_token and unsubscribed_trailer precisely. The prose confirms which fields are editable but adds no format or syntax detail beyond the schema; notably localizations (a nested object) is not mentioned in the description at all.

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 names a specific verb ('Change') plus the exact editable fields of the channel resource (description, keywords, country, default language, unsubscribed trailer), which cleanly separates it from siblings like set_channel_banner, set_watermark, or update_video.

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?

It explains partial-update semantics ('Only the fields you pass change'), states the precondition that the user must confirm because the fields are public, and gives an explicit exclusion (channel name/handle must be edited in YouTube Studio). It never names a sibling tool such as get_channel or set_default_channel to read state first, so it stops short of full alternative routing.

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