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

Annotations already cover readOnly/idempotent/non-destructive/openWorld, so the description correctly focuses on behavior the annotations cannot express: the URL is short-lived and must be used promptly, and the payload is an undecoded scientific binary. The expiry disclosure is valuable, though it stays vague ('short-lived') rather than giving any concrete TTL.

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?

Four sentences, front-loaded with purpose and return values before the usage example and the binary caveat. The dataset/version/filename example partially duplicates the schema's examples array, but it earns its place by tying the arguments to a real-world filename pattern.

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 compensates by naming the four returned fields (signed URL, content type, byte size, last-modified) and flagging the URL's ephemerality. It is complete enough to invoke correctly, with the only unstated item being any auth/rate-limit expectations.

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 100%, so all three parameters are already documented, making 3 the baseline. The description adds marginal value by tying 'filename' to the knmi_dataset_files tool as its source and by supplying a second worked example with a real dataset name, reinforcing the expected string formats.

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 opens with a specific verb and resource ('Mint a temporary download URL for one file in a KNMI Data Platform dataset'), which is immediately distinguishable from siblings like knmi_datasets (enumerate datasets) and knmi_dataset_files (list files). It also explicitly states the scope is a single file, not a dataset or a batch.

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 tells the agent where the required filename comes from ('Pass a filename from knmi_dataset_files') and gives a concrete dataset/version/filename example, which is clear routing context. It stops short of explicit when-not guidance, e.g. what to do if the URL expires or whether to use knmi_dataset_files first.

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