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

Annotations already mark it as read-only, idempotent, and non-destructive. The description adds useful behavioral context: the optional dataset_slug returns a link to the dataset page where a key is minted, and the tool's role is purely informational. No contradictions with annotations.

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?

Three sentences each serve a distinct purpose: describing content, explaining the optional parameter, and stating when to call. The opening sentence is a dense list but not bloated; every part earns its place.

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 tool with one optional parameter, no output schema, and safety-bearing annotations, the description covers what the tool returns, how the optional parameter changes behavior, and when to invoke it. No critical information is missing.

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?

The only parameter, dataset_slug, is named, marked optional, given an example value ('kden-metar-hourly'), and its effect is clearly explained. This fully compensates for the 0% schema description 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 clearly identifies the tool as returning access instructions: what is anonymous, what needs an account, API key classes, OAuth, signup URL, and numbered steps. It is specific and distinct from data-fetching siblings, though it does not explicitly name a sibling or contrast itself with other instruction tools.

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 gives explicit trigger conditions: 'Call this whenever a tool refuses for want of authentication, or before telling a user they need to sign up.' This is strong situational guidance, but it does not mention when not to use the tool or name alternatives.

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