Update Channel

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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds genuine context the annotations lack: a quota cost ('51 units') and confirmation that this is a partial-update operation. It does not explain what destruction means concretely (e.g. that keywords replace the existing set), which the schema carries instead.

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 short sentences, front-loaded with the primary purpose, then the patch rule, then the exclusion. Every sentence carries distinct information; the quota note is set off and easy to scan.

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?

An output schema exists, so return values need not be described, and the schema fully documents all six optional parameters. Combined with annotations covering safety and the description covering quota and patch behavior, an agent has what it needs. The only gap is concrete disclosure of replacement semantics, which the schema partially covers.

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% and all six parameters carry individual documentation, so the baseline is 3. The description's 'only the fields you pass change' adds a useful cross-parameter rule, but it adds no syntax or format detail beyond the schema.

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?

States a specific verb and resource: 'Change your channel's about info.' It also carves out a hard scope limit ('The name can only be changed in Studio'), which separates it from sibling tools that manage other channel assets. It is clear, though it never explicitly names the sibling it complements (e.g. set_channel_banner, set_watermark).

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?

'Only the fields you pass change' establishes patch semantics, telling the agent that omitting a field is safe rather than destructive. The note that the name must be changed in Studio is an explicit when-not pointer to another surface. No guidance is offered on when to prefer this over the banner/watermark siblings, but the routing hints are useful.

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