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

readOnlyHint=true already establishes this is a safe read, so the description's remaining burden is small. It adds the underlying REST endpoint (GET /virtual-keys) and clarifies the resource semantics, but says nothing about ordering, pagination behavior, or volume of results.

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 tight sentences, front-loaded with the action and resource, followed by a compact clarifying definition and the endpoint. No wasted words.

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?

A read-only list tool with fully documented params and annotations covering the safety profile needs little more. The description handles the resource definition adequately; only the absence of any note about pagination/large result sets keeps it short of full marks.

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 page_size and current_page are fully documented with defaults in the schema itself. The description adds no parameter detail beyond that, which is the expected baseline when the schema carries the load.

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?

States a specific verb+resource ('List virtual keys') and adds a useful definition of what a virtual key is (aliases mapping to provider credentials plus budget/rate limits). The plural 'List' implicitly distinguishes it from the sibling portkey_get_virtual_key, but no sibling is named explicitly.

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?

There is no when-to-use guidance: nothing tells the agent when to pick this over portkey_get_virtual_key (fetch one key), nor any mention of pagination strategy for iterating a large collection. The usage context is left entirely to inference from the name.

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