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

Annotations only say it is a non-read-only, open-world, non-destructive call. The description adds substantial context: what the email contains, that subject/message come from Messaging Templates unless overridden, that it reaches real people requiring user confirmation, and that a Cotlet API key with app access is required.

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?

Purpose is front-loaded and the sentences are compact, but the confirmation point is stated twice ('you confirm each call' and 'confirm with the user before each call'), which is minor 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?

There is no output schema, and the description does not attempt to explain a return value, which is fine. Combined with annotations covering the safety profile and a comprehensive explanation of recipients, templates, confirmation, and auth, it is nearly complete; only the PDF attachment behavior is left implicit.

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 each parameter already documents its own default. The description largely restates this (template-driven subject/message, cc addresses, main customer as default 'to') and omits attach_pdf and job_number, so it stays at the baseline.

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?

Specific verb (Email/send) plus resource (the estimate of an opportunity), with the recipient scope ('main customer of the job') spelled out. This cleanly separates it from kickserv_send_invoice and the generate/create siblings without requiring a schema read.

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 context for when to use it (emailing an estimate to the customer) and notes the default confirmation behavior and that it can be turned off. It does not name an explicit alternative tool, so it falls just short of a 5.

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