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

Annotations already declare readOnlyHint=true, so the agent knows it's safe. The description adds behavioral context about pagination, type filtering, and sorting, plus the REST method (GET) which reinforces the read-only nature. However, it does not disclose details like rate limits, authentication specifics, or return format, which are not covered by annotations. This is comparable to the calibration example where a 3 was given.

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 extremely concise, with only three short sentences: the core action, the pagination/filter/sort features, and the REST endpoint. It is front-loaded with the verb and resource, and every sentence adds value. No fluff or repetition.

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?

The tool is simple, has a readOnlyHint, and a fully described schema. The description covers the resource, pagination, and filtering. It does not explain the return shape, but no output schema exists, and for a list endpoint this is often predictable. The description is complete enough for most use cases.

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 100%, so all five parameters already have descriptions. The description adds a high-level mention of 'optional type filter and sort' but does not provide any new semantic details beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 the action ('List') and the resource ('the account's email templates'), with a parenthetical clarifying 'saved and pre-built layouts'. This is specific and distinguishes it from sibling list tools that target different resources (audiences, campaigns, members).

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 for when to use the tool: to list email templates. It mentions pagination and optional type filter and sort, which indicates how to customize the request. It does not explicitly name alternatives or when-not-to-use scenarios, but given the unique resource (templates), the usage context is clear enough.

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