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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the read-safety profile is covered. The description adds value beyond them: the returned fields, the Personalize behavior (Perfect Venue fills fields per event), and an auth requirement (Cotlet API key with access to this app).

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?

It is front-loaded and reasonably sized, but the opening two sentences restate the same fact ('template emails from Settings, Email' vs 'Returns the template emails you set up in Settings, Email'), so not 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?

With no output schema, the description carries the return-value burden and does so by naming the fields returned. Combined with auth needs and the downstream template_id usage, an agent has enough to call and apply the result; only minor gaps (no pagination/ordering note) remain.

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?

The tool takes zero parameters, which is the baseline-4 case. The only parameter-like mention (template_id) refers to a downstream tool, not this one's inputs, so there is nothing further the description needs to document.

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 (list email templates) and names the exact fields returned (name, subject, text) and their source (Settings, Email). An agent can distinguish this from siblings like list_events or send_email without opening any 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?

Explicitly routes usage: 'Use a template_id from this list in send_email,' tying the tool to its downstream consumer. Clear context, but no explicit when-not-to-use or alternative listing tool named, which keeps it at 4 rather than 5.

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