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

Beyond the annotations (which only say it is a non-destructive, non-read-only write), it discloses meaningful behavior: status is always forced to inactive, and design/HTML cannot be set through MCP. That is exactly the kind of constraint an agent needs before calling, though it says nothing about auth requirements or failure modes.

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 the create action and the inactive-draft constraint, then the parameters, then the follow-up workflow. Dense but every clause carries information; no filler.

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 mutation tool with no output schema, it closes the loop by noting the return shape mirrors email_get, and it explains what the tool cannot do. The only remaining gap is organization_id semantics and any permission requirements.

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 each parameter is already documented in the schema. The description restates required vs optional and the apps_list provenance for app_id, but says nothing about organization_id and how it changes app_id resolution — that detail lives only in the 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 and resource ("Creates a new email template") plus a strong differentiating qualifier: it is created as an inactive draft, which cleanly separates it from email_update and email_get.

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?

Gives clear operating context — required name, optional subject/preview_text, app_id sourced from apps_list — and explicitly routes body editing/activation to the Meridian dashboard. It never names email_update as the alternative for those subsequent edits, so the routing is by destination rather than by sibling tool.

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