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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered; the description usefully adds that the return value is guidance for the assistant to apply rather than generated copy or saved feedback. That is real behavioral information, especially since there is no output schema. The omit-guideId-to-list behavior is also disclosed.

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 when-to-use trigger, then the return-nature caveat, then the parameter behavior. No filler and nothing repeated from the schema or 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?

With a single optional enum parameter, no output schema and read-only annotations, the description covers trigger, return nature and the listing mode well. The only mild gap is any hint about the shape or volume of the returned guidance, which matters for an agent planning its next step, but that is a minor omission.

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 must carry the param burden, and it largely does: its four listed activities correspond in order to the enum values visual-copy, carousel-stories, visual-design and human-review. It also explains that guideId is optional via 'Omit guideId to list guides.' It never names the enum values literally, so the mapping requires a small inference.

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 uses a specific verb ('Read') plus a specific resource ('practical guidance') and enumerates the four guidance domains, which map to the four enum values. It also clarifies what the tool does NOT return ('not generated copy or saved feedback'), which separates it from the creation/review siblings. It stops short of naming a specific sibling tool it might be confused with, such as get_example or get_template.

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?

'Read practical guidance before drafting ... copy, choosing carousel stories, designing visuals or recording human feedback' gives explicit trigger conditions tied to four concrete tasks. It also gives a mode-selection rule: 'Omit guideId to list guides.' It does not state when NOT to use it or name an alternative tool, so it falls 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.