update_poster

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

With no annotations, the description carries the full burden. It discloses that a revision backup is made first, which is a useful safety behavior, but it does not clarify whether unspecified fields are merged or replaced, auth requirements, or any validation/destructive effects. This is minimal but not misleading.

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 exactly two sentences, front-loaded with the core purpose and then the backup behavior. No wasted words, and it is highly readable.

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?

Given the tool's complexity (8 parameters, nested objects, no output schema, no annotations), the description is too sparse. It does not explain how the update interacts with existing content (merge vs replace), return values, or any error conditions. The backup note is helpful but far from adequate for a tool of this scale.

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 compensate, but it only mentions 'content/theme fields' generally. It does not explain any specific parameter beyond that, leaving the nested content object and other fields (mood, notes, style, status, etc.) completely unexplained. This is insufficient for such a complex 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?

The description clearly states the tool updates an existing poster's source HTML/CSS via structured fields, which distinguishes it from create_poster (creation) and render_poster (rendering). The verb 'update' and resource 'existing poster' are specific and unambiguous.

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 implies usage for existing posters being modified through structured fields, giving context that this is not for raw HTML edits or new posters. However, it does not explicitly name alternatives like create_poster or mention when not to use it, so it stops short of a perfect 5.

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