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

Annotations only declare destructiveHint=true; the description goes further by warning that this SENDS A REAL EMAIL to the customer address, which conveys the irreversible external side effect. It does not cover send timing, permissions required, or failure behavior, so it falls short of 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?

Three short sentences, no waste, with the write/side-effect warning front-loaded ahead of the alternative-tool routing. Every sentence earns 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?

Covers the side effect, the sibling routing, and the underlying endpoint for a six-parameter mutation tool with no output schema. It omits what the call returns and whether sending is immediate or queued, which are minor gaps given the annotations and full schema coverage.

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%, so all six parameters are already documented in the schema. The description only echoes that `to` is the recipient customer address, adding no syntax, format, or constraint detail beyond the structured fields. 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 ('send an outbound reply on a ticket') with a front-loaded WRITE marker, and explicitly distinguishes itself from the sibling enchant_add_note (internal note). An agent can select this over nearby tools without opening a schema.

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?

Names the alternative tool (enchant_add_note) and the condition that selects it (internal vs. customer-facing), which is exactly the decision boundary an agent needs. Also grounds the call in the underlying REST operation for verification.

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