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

No annotations are present, so the description carries the full burden of behavioral disclosure. It discloses that selection is deterministic via 'hash of date+level' and that the same word is returned all day, which is a key behavioral trait. It also enumerates the returned fields, adding clarity beyond the bare tool name, though it does not discuss error semantics or timezone assumptions.

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 compact and well structured, with purpose, parameter guidance, behavior, and return format each on their own line. Every sentence adds value, and there is no filler. The deterministic-selection note is especially useful and placed where it is easy to notice.

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 read-only tool, this description covers the essential selection criteria and output shape. It lacks a precise definition of what 'date' refers to and does not explain the possible values of the 'status' field, but these are minor gaps given the tool's simplicity and the presence of an output schema.

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 0% and there are no enums, so the description must compensate. It does so by specifying 'level: A1 | A2', which defines the only parameter's allowed values. It does not elaborate on what happens with invalid values or whether 'A1' and 'A2' are case-sensitive, but the core semantic is present.

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 clearly identifies the tool's resource: 'German word of the day with translations + IPA + examples' and explicitly states the return shape. Although it lacks an imperative verb like 'get', saying 'Returns dict' describes the operation precisely. It is also easily distinguishable from all sibling tools, none of which are word-of-day retrievers.

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 implies the use case: call when you need a German word of the day for A1 or A2. However, it does not explicitly state when to prefer this tool over alternatives or provide exclusions. There are no directly competing siblings, so the omission is not severely harmful, but explicit guidance is still absent.

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