Open the Deepy top-up page

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

Annotations already indicate readOnly and non-destructive, so the bar is lower. The description adds valuable context beyond annotations: it opens a browser page, returns its URL, and explicitly clarifies no financial transaction occurs. This meaningfully supplements the structured hints.

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?

Two sentences, no fluff. The first sentence states the core action and return value; the second provides usage trigger and a crucial safety clarification. Every sentence 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?

The tool is simple (zero params) and the description covers its purpose, trigger conditions, side-effect-free nature, and return value. No output schema exists, but the description explicitly mentions what it returns, making the tool fully understandable.

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?

There are no parameters, so the baseline is 4. The description adds no parameter details because none exist, but it does specify the tool's return value (the URL), which is useful. No gap.

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 the specific verb 'Open' plus the resource 'Deepy credits top-up page', and adds the exact behavior: opening in the default browser and returning the URL. This clearly distinguishes it from sibling generation tools like deepy_estimate_generation and deepy_create_generation.

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?

Explicitly states when to call: when a balance is too low to cover a generation, citing deepy_estimate_generation returning canAfford=false or a create failing with INSUFFICIENT_CREDITS. It also gives a clear exclusion: 'Opens a page only — it never moves money or charges anything.'

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