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

There are no annotations, so the description carries the transparency burden. It discloses the critical behavior that providing steps replaces all existing steps, which is valuable. However, it does not clarify whether other fields are partially or fully replaced, nor does it mention permissions or return behavior.

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 two concise sentences with the key caveat front-loaded. Every word earns its place and there is no redundancy with the schema.

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?

The tool has no annotations or output schema, so the description carries a heavy burden. It covers the steps replacement behavior and the schema details well, but lacks explicit partial-update semantics for other fields and any mention of response or prerequisites, leaving some ambiguity.

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 descriptions cover 75% of parameters, but the description adds key semantic value by explaining that steps replace all existing steps. This goes beyond the schema's 'Replacement steps' wording and clarifies behavior for the most complex parameter.

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 and resource ('Update a page fragment') and clearly distinguishes this from sibling tools like create_page_fragment and delete_page_fragment. The added sentence about steps replacement reinforces the purpose.

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?

The description clearly implies use when modifying an existing page fragment, and the steps replacement note provides important context. However, it does not explicitly mention when not to use it or direct users to create_page_fragment for new fragments.

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