list_capabilities

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

With no annotations, the description carries the full behavioral burden, yet only 'List' implies a read-only, non-mutating operation. It adds the useful scoping detail that results are 'this endpoint's' credential-use capabilities, but says nothing about scope breadth, permissions, or whether the list can be filtered.

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?

A single focused sentence with no padding, front-loaded with the verb. Its brevity is appropriate, though that brevity is also what leaves the meaning of 'capabilities' unstated.

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?

An output schema exists, so return values need no explanation, and the lack of parameters keeps the contract simple. What is missing is any routing help against describe_capability and invoke_capability, which is the main decision an agent must make among these three siblings.

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 tool takes no parameters, so there is nothing to document and the description cannot compensate for a gap that does not exist. Baseline 4 applies for a zero-parameter tool.

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 pairs a specific verb ('List') with a specific resource ('this endpoint's credential-use capabilities'), which is enough for an agent to grasp the operation. It does not, however, explicitly distinguish itself from describe_capability or invoke_capability, and 'capabilities' is left largely undefined, so sibling differentiation is only implied.

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, no prerequisite, and no mention of the sibling tools. An agent must infer that this is the enumeration step used before describe_capability or invoke_capability.

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