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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds only topical examples and says nothing about matching behavior (keyword vs. semantic), result volume, or ordering—modest added value given the annotation coverage.

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 with the source and purpose before the examples. No filler, though the examples consume roughly half the text.

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 single-parameter search tool with rich annotations and no output schema, the essentials are present, but the description omits how matching works and what an agent should expect back, leaving a small gap an agent could stumble on.

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?

With schema coverage at 0%, the description carries the burden; the example topics do clarify what 'onderwerp' should contain. However, it gives no guidance on phrasing, language, or the documented 2–60 character constraint, so the one parameter is only partially explained.

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?

States a specific verb (zoek) and resource (artikelen) tied to the Cosmic Journal source, and the examples ('Mercurius retrograde, volle maan of een sterrenbeeld') make the scope concrete. It implicitly separates itself from horoscope-generating siblings, but never names them.

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?

'over een onderwerp' plus the example topics implies when to use it (topical article lookup), but there is no explicit when-to-use/when-not guidance and no reference to alternatives like daghoroscoop or maankalender for date-based queries.

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