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

The annotations already establish read-only, idempotent, non-destructive behavior. The description adds the categories of material returned and the claims restriction, but provides no further context about the resource's scope, freshness, or how the listed rejections should influence subsequent drafts.

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 single compact line is front-loaded with the writing rules, and every listed item adds distinct information. The claims restriction is expressed efficiently without filler or repetition.

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 simple zero-argument reference read, enumerating rules, facts, examples, and reasoned rejections is nearly enough to invoke and interpret it. With no output schema and several mail-related siblings, workflow placement and the scope or structure of the returned material remain small but meaningful gaps.

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?

There are no parameters, so no parameter explanation is necessary and the zero-parameter baseline of 4 applies. The description appropriately focuses on the resource's contents rather than inventing input-related detail.

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?

Together with the title, the description clearly identifies a readable mail-style resource containing writing rules, a fact sheet, approved examples, and rejections with reasons. It does not explicitly distinguish this reference tool from siblings such as crm_mail_concept or crm_mail_te_schrijven.

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?

The parenthetical 'alleen deze claims gebruiken' provides a useful constraint: factual claims must come from the supplied fact sheet. However, it does not say when to consult the tool, whether doing so is required before drafting, or which sibling should be used to create the actual email.

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