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

Annotations already cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the bar is lower. The description adds genuine behavior beyond them: new projects inherit channel style, the style prerequisite, and that a web_url is returned for the user to follow — all useful side-effect context.

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 with the mutation scope front-loaded, followed by the dependency and the follow-up instruction. No repetition or filler, though it could be slightly more ordered around the action enum.

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 multi-action mutation tool with no output schema, the description covers scope, prerequisite, and return signal (web_url). An agent has enough to invoke it correctly; remaining gaps are minor given the rich schema and annotations.

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 schema already documents every parameter including the action enum semantics. The description only echoes title/brief/video_format, adding no syntax or format detail beyond the schema; baseline 3 applies.

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 gives a concrete verb set (create/change) and the exact resources and fields affected (channel, project, title, brief, video_format). An agent can distinguish it from projects_read by the mutation framing, though it never names the read sibling explicitly.

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 supplies a real workflow prerequisite: a channel with no style needs style_edit action=create before anything is generated, and it tells the agent to surface the returned web_url. No explicit when-not or negative routing to alternatives is given, so it stops short of a 5.

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