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

Annotations already establish it is a non-read-only, idempotent, non-destructive write. The description goes beyond them by disclosing the default-sender fallback and the refusal failure mode, so the agent knows activation can fail and why emails are never sent from an unset address.

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 tightly written sentences that lead with the purpose and then add precondition and failure behavior, with no filler or redundancy.

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 one-parameter tool with full schema coverage and no output schema, the description covers the effect, the precondition, and the failure fallback, leaving nothing an agent needs to call it correctly.

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% and there is a single uuid parameter fully documented in the schema; the description adds no further parameter meaning, so the 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 (activate) plus resource (sequence) and the concrete effect — it 'starts enrolling and processing contacts' — which clearly separates it from siblings like meisa_activate_trigger or meisa_pause_sequence.

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?

It gives a precondition ('The sequence must have at least one step'), which is useful when-to-use context, but it never routes the agent among alternatives (pause, resume, enroll_in_sequence) or states when not to activate.

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