use-template

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

With no annotations provided, the description carries the burden of disclosing behavior. It states that the tool creates a draft in Mail.app for review/send, not an immediate send, and returns a confirmation. It does not mention potential side effects on the template, but the core behavior is well 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?

The description is concise and front-loaded with a direct 'Use when' statement. Every sentence adds value, clearly stating purpose, return value, and exclusions without unnecessary detail.

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 5 params and an output schema, the description covers the essential use case, return value, and alternatives. It is sufficiently complete given the simplicity of the operation and the presence of an output schema.

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 80%, so baseline is 3. The description adds meaning by explaining the id is a template id and that recipients/subject/body are optional overrides. This clarifies the workflow beyond the schema, especially for the undocumented id 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 clearly states that the tool composes a new draft from a saved template by id, with optional overrides for recipients, subject, or body. It explicitly distinguishes itself from get-template and send-email, naming these sibling tools.

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?

Provides explicit 'Use when' and 'Do not use when' guidance with named alternatives (get-template, send-email). This makes the appropriate context and exclusions unambiguous.

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