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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds real value by naming the underlying state mutation (is_active=true) and framing the call as a shortcut over update_trigger, clarifying it is a non-destructive, repeatable write. It does not mention auth or failure modes, so not a 5.

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 short sentences, front-loaded with the action and its effect, with the alternative-route note second. No filler and nothing that fails to earn its place.

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, non-destructive, idempotent toggle with no output schema, the description supplies everything an agent needs: what it does, what state it sets, and how it relates to the sibling update tool. Nothing material is missing.

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% and the single parameter (trigger_id, UUID) is fully documented in the schema, so the description carries no additional parameter burden. Baseline 3 applies; the description adds nothing beyond what the schema already states.

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) and resource (email trigger) plus the concrete effect (accepts send requests, sets is_active=true). It is clearly distinguishable from the sibling meisa_deactivate_trigger and from the generic meisa_update_trigger.

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 explicitly names the alternative path ('Ergonomic shortcut for toggling is_active via meisa_update_trigger'), telling the agent this is the narrow, preferred call for activation. It does not spell out exclusions (e.g., when to prefer update_trigger instead), so it stops short of a full when/when-not statement.

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