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

The description reveals important behavioral details beyond the readOnlyHint annotation: the prompt binds to the brief, acceptance rubric, and opportunity context fetched from the account, and 'degrades to generic writing advice without them.' It also discloses per-channel methodology, giving an agent a realistic model of what the prompt will contain.

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 front-loaded with purpose, then behavioral context, then parameter guidance. It is dense but every sentence adds necessary information: what the tool does, how it behaves contextually, which channel values exist, and what each produces. There is no filler or redundancy.

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?

With one enum parameter, a readOnly annotation, and no output schema, the description provides everything needed to call the tool correctly: the exact channel values, their meaning, the default, the expected behavior, and the fallback behavior. Returning a prompt is self-evident, so no return-format explanation is necessary.

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 0%, so the description carries the full burden for the `channel` parameter. It lists all enum values, explains what each channel covers, and notes the default. This fully compensates for the schema's lack of parameter descriptions.

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 states a specific action ('Get the writer system prompt') and resource ('for drafting one content type from its brief'), and further differentiates the tool from siblings by spelling out that each channel has its own methodology. This is far more specific than the title alone and leaves no ambiguity about what the tool returns.

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 explicitly instructs when to use the tool: 'Load the prompt for the channel you are about to draft' and states that article is the default. It also explains what each channel is for ('article covers voice adaptation... reels and youtube cover production script'). It does not name alternatives or explicitly say when not to use it, but the context is clear.

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