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

Annotations already indicate this is a mutating, non-idempotent, non-destructive operation. The description adds that it saves a template from the editor, but does not disclose return behavior, validation requirements, or side effects like the isDefault replacement behavior (which is only in the schema). No contradiction with annotations.

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?

Two sentences: the first clearly states the action, the second enumerates required and optional parameters. Every word adds value, and it is front-loaded with the primary purpose.

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 tool with 6 parameters, a nested object, and no output schema, the description is functional but incomplete. It does not mention what the tool returns, how validation fails, or the implications of isDefault/isPublic. It provides a basic overview but leaves gaps for an agent to infer.

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 coverage is 67% (4 out of 6 params have descriptions), and the description adds a brief summary of required vs. optional parameters without introducing new meaning beyond the schema. It highlights 'template' as required and lists the optional fields, which is helpful but not a significant addition.

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 exactly what the tool does with a specific verb ('Save a new') and resource ('custom template'), and adds the context of being authored in the drag-and-drop editor. This clearly distinguishes it from sibling tools like apply_template and update_template by emphasizing 'new.'

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 provides clear context: use this tool when you have authored a new custom template in the editor. It does not explicitly name alternatives or when-not-to-use scenarios, but the 'new' wording implicitly contrasts with update/apply operations. This is sufficient context for an agent to select it appropriately.

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