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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds that the comparison includes licensing costs (Buma/Stemra en Sena) where applicable, which is useful context but not a behavioral disclosure beyond what annotations imply. It does not mention output format or limitations, but with annotations covering side effects, a score of 3 is appropriate.

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 description is two sentences, concise and front-loaded with the main action ('Zet de jaarkosten naast elkaar'). It includes the target audience and purpose without unnecessary detail. It is efficient and well-structured, earning a high score.

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 7 parameters, no output schema, and only safety annotations, the description needs to explain what the tool returns and how inputs affect results. It does not. It fails to mention that the comparison is based on business context (e.g., type of business, surface area), and it does not describe the output (e.g., a table of costs). This leaves significant gaps for an agent trying to call the tool correctly.

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 43%, which is low, so the description should compensate by explaining how parameters affect the comparison. It does not. The description says nothing about how 'soort_zaak', 'fte', 'oppervlakte_m2', etc. influence the cost comparison. The schema provides descriptions for only three parameters, leaving four unexplained. The description adds no value beyond the schema, failing 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 uses a specific verb ('Zet ... naast elkaar') and resource ('jaarkosten voor radio, streamingdienst, rechtenvrije aanbieder en RadioMatic'), clearly distinguishing it from siblings by focusing on cost comparison across multiple options. It also states the intended audience and goal, leaving no ambiguity about what the tool does.

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 description explicitly states the use case: for businesses wanting to compare music options or find a cheaper alternative to their current service. It provides clear context for when to use the tool, though it does not explicitly name alternatives or state when not to use it. The sibling list includes 'pakketten_en_prijzen' and 'bereken_licentiekosten', but the description's focus on side-by-side cost comparison is sufficient to guide selection.

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