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

Annotations already establish the safe read-only, non-destructive profile, so the bar is lower. The description adds useful context by naming the return payload (last-verified date and user-vote success rate), but says nothing about permissions, rate limits, or behavior when no code exists.

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, front-loaded sentence that packs the resource, scope, and return fields without any filler. Well structured for quick scanning.

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 lookup with no output schema, the description adequately conveys what is retrieved and what extra metadata accompanies the code. It falls short only on edge-case behavior (e.g., missing codes), which is minor here.

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 only 50% (merk is undocumented in the schema), so the description should compensate, but it merely restates that a brand and a market are involved. It adds no format or semantic detail for merk and nothing beyond the schema's own markt description.

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?

Names a specific resource (kortingscode) with scope (brand + chosen market) and the extra data returned (last-verified date, success rate). It is clearly distinct from the product/sales siblings, though it lacks an explicit verb.

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?

No guidance on when to use this versus alternatives, no prerequisites or exclusions. Usage is only implied by the noun phrase 'voor een merk in de gekozen markt'.

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