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

Annotations only provide generic write/non-idempotent hints; the description adds the substance: it creates a lead rather than an account, the applicant receives a confirmation email, a human follows up, and the returned link contains attribution query parameters that must be passed through unchanged. This is exactly the beyond-annotation context the agent needs for a state-changing call.

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?

Three sentences, front-loaded with what the tool does, then the not-an-account clarification, then the link-passing instruction. The em-dash aside is slightly dense but every sentence carries actionable information; nothing is wasted.

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 correctly explains the returned registration link and how to hand it to the user, and it covers side effects and the attribution requirement. The only real gap is the undocumented optional parameters, which is a schema-side shortfall rather than a description failure.

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 description coverage is only 25% (only email is documented), and the description adds no parameter-level meaning beyond restating that the email receives the confirmation. The meaning of naam, telefoon and bedrijfsnaam is left entirely to the schema's patterns and length constraints, so it fails to compensate for the low coverage.

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 concrete action (registering a trial-request lead at Taklo) and its output (a registration link), and explicitly draws the boundary that it does NOT create an account. That boundary implicitly separates it from the other Taklo tools, though no sibling is named directly, so it lands just short of a 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?

It states the trigger condition clearly ('iemand de 14-dagen-gratis-proefperiode wil starten') and clarifies that account completion happens elsewhere, giving the agent a real usage context. It stops short of naming an alternative tool or an explicit when-not-to-use case, so it is not a 5.

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