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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuinely useful behavior beyond that: it discloses the underlying GET /v1/emailtemplate endpoint and the pagination contract (next_offset feeding into offset), which the annotations do not carry.

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?

Three short, front-loaded sentences with no filler. The purpose leads, followed by the pagination note and endpoint, which is the right ordering for a simple list tool.

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 read-only listing tool with two fully documented optional params and annotations covering safety, this is nearly complete. The only minor gap is that nothing indicates what a returned template looks like, though no output schema exists to carry that.

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 description coverage is 100%, so both limit and offset are already fully documented in the schema. The description adds only a cross-reference on how next_offset maps to offset, which is a marginal addition over the schema baseline of 3.

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 (e-mail templates), which cleanly separates it from sibling list tools like list_invoice_templates and list_ledgers. It does not, however, explicitly name or contrast with any sibling, so it stops short of a 5.

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 pagination sentence ('pass next_offset as offset') gives concrete operational guidance for continuing a result set, but there is no statement of when to use this tool versus alternatives or any exclusions. Usage is only implied.

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