create_template

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

Annotations only provide destructiveHint: false, which is minimal. The description compensates by disclosing key behaviors: placeholder auto-detection and storage, and failure on duplicate names. This adds meaningful context beyond the sparse annotation, though it does not mention return values or authentication.

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, front-loaded with the core purpose. The first sentence states what the tool does; the second adds important behavior and failure mode. There is no filler, tautology, or redundant information.

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 simple creation tool with full schema coverage, the description covers the essential elements: purpose, placeholder behavior, and duplicate handling. It does not explain return values, but no output schema exists and the tool's simplicity mitigates the need. It is sufficiently complete for an agent to use correctly.

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?

The input schema already provides 100% description coverage for all four parameters, so the baseline is 3. The description adds a small behavioral note about placeholders in subject/body but does not materially enhance parameter semantics beyond the schema. It correctly leaves detailed parameter meaning to the 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 opens with 'Save a reusable email template', a specific verb+resource that clearly defines the tool's function. It distinguishes from sibling tools like list_templates, get_template, delete_template, and render_template by focusing on the creation action. Additional details about placeholders and uniqueness add clarity without ambiguity.

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 when to use this tool (to save a new reusable template) and provides a practical guideline: it fails on duplicate names, so you must delete the existing template first to replace it. However, it does not explicitly name alternative tools or state when not to use this tool, so it stops 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.