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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real behavioral facts: documents are returned as names only with no content, capped at 25 per category, activities are limited to the last 20, and a `meer` field reports how many items were withheld. That truncation behavior is exactly the kind of thing an agent needs and cannot get from annotations.

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?

A single dense sentence, front-loaded with the resource ('Dossier van één contact') followed by the returned contents and caps. Nearly every clause carries information, though the parenthetical limits and the `meer` remark make it slightly harder to parse at a glance.

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 takes on the job of describing the return payload and does so well, including contents, caps and the `meer` counter. What is missing is edge behavior: resolution when both identifiers are given, and what an agent should expect when the contact is not found.

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%, so the schema already documents both fields, and the description only reiterates that contact_id or email may be supplied. It does hint at an either/or lookup pattern, which is mild added meaning, but it never says what happens if both or neither is provided.

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 names a specific resource and scope: the dossier of a single contact, enumerating its contents (details, company, deals, linked document names, recent activities). That is clearly distinguishable from list-style siblings like crm_contacten or crm_bedrijven, though no sibling is named explicitly, keeping it at 4 rather than 5.

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?

Invocation is addressed ('Geef contact_id of email'), so the agent knows either identifier works, but there is no guidance on when to choose this tool over crm_contacten or crm_zoek, and no prerequisites or exclusions are stated. Usage is implied rather than explained.

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