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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds valuable behavioral context beyond that: it returns text and makes explicit that nothing is applied to a campaign until passed to flow_set or sequence_update.

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 tightly written sentences: the return content comes first, followed by the downstream-effect constraint. No filler, and the most decision-relevant information is front-loaded.

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?

No output schema exists, but the description discloses the return shape ('Returns text', body and subject), which is what an agent needs. Only minor gap is no mention of behavior when templateId is invalid or not found.

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?

Single required parameter with 100% schema description coverage ('Template id, from `template_list`'). The description adds no further parameter detail, which is acceptable given the schema already does the work — baseline 3 applies.

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 and resource ('Full body and subject of one saved template') and makes clear it is a single-item retrieval, distinguishing it from template_list and template_upsert. An agent immediately knows what it gets back.

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?

Explains the intended downstream usage — pasting into a sequence step or adapting for a new campaign — and names the two consumers, flow_set and sequence_update. Missing an explicit statement of when to use it versus template_list, though the schema's 'from `template_list`' hint partly covers that.

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