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

Annotations already declare readOnly=true, idempotent=true, destructive=false, so the safety profile is covered. The description adds the non-obvious behavior that it only returns instructions and performs no side effect, which resolves a potentially dangerous misreading of the name. It omits pricing/permission or rate-limit context, and the trailing 'Exact Online's official API: Yes' is cryptic rather than informative.

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?

The workflow information is front-loaded and useful, but the definition carries filler: 'from ChatGPT, Claude or any AI agent' adds nothing operational, and the fragment 'Exact Online's official API: Yes.' is ambiguous prose that could also mean the tool calls the official API, which it does not.

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 compensates by saying the return value is step-by-step instructions covering screens, buttons, and fields. Combined with the follow-up pointer to browser tools, an agent knows what to expect and what to do next; only the meaning of the API line is left unclear.

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, so the baseline is 4. The description correctly adds no parameter guidance, and there is nothing in the empty schema needing compensation.

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?

The description pairs the specific verb+resource (sending an invoice in the user's own Exact Online account) with the surprising true function: it returns step-by-step instructions rather than performing the send. That clarification is what makes it usable, though an agent skimming only the name would still expect an action tool, and nothing distinguishes it from the sibling exact_online_create_sales_invoice.

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 an explicit workflow: call this to get the screens/buttons/fields, then execute with the cotlet_browser_* tools in the Cloud Browser. It also states it opens nothing by itself, which prevents misuse. It stops short of saying when to prefer an API-based sibling over this guide-plus-browser path.

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