templates

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds the empty-state behavior ('says so when there are none yet'), which is genuine context beyond the structured fields. It does not discuss pagination or ordering, but for a no-param read-only list tool the annotation bar is already met.

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?

Front-loaded with what is listed, then the routing guidance; every clause carries information. The single compound sentence with semicolons is dense, but not padded or repetitive.

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 zero-argument read-only list with an output schema and strong annotations, the description covers purpose, alternatives, and empty-state handling, so an agent has what it needs to call it. It adds little about ordering/limits, but nothing essential is missing.

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 tool takes zero parameters and schema coverage is 100%, so there is no parameter semantics to explain; the baseline for a 0-param tool is 4. The description instead documents the response fields, which is informative but belongs to the output 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?

States a specific verb (List) and resource (saved email templates) plus the exact fields returned (number, name, subject, last-changed date). It is readily distinguishable from siblings template, draft, and change_setting, which it names.

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?

Explicitly routes the agent: use template to see one in full with placeholders, draft(template=...) to write an email from it, and change_setting for add/change/delete. Both the alternative tools and the conditions that select them are stated, leaving nothing to inference.

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