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

Annotations already declare readOnlyHint=false and destructiveHint=false, so mutability is covered. The description adds useful prerequisite semantics (at least one capability per kernel before job submission) but says nothing about idempotency, permissions, or what is returned after registration.

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 short sentences, front-loaded with the core action and then the critical prerequisite. The third sentence largely restates the schema's type enum examples, which is slightly redundant but not wasteful enough to hurt.

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 mutation tool with no output schema, the description covers the action, the essential prerequisite, and the nominal types. The notable remaining gap is that it never indicates what the call yields (e.g. a capability ID the agent would need later for job submission), which matters given the stated ordering dependency.

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% with 4 documented parameters, so the schema carries parameter meaning. The description's type examples duplicate the schema's own type description and add no format, constraint, or validation detail beyond it.

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 ('Register') and resource ('a capability instance for a kernel'), and the third sentence enumerates capability types, so the agent knows what gets created. It stops short of explicitly differentiating from near-siblings like register_capability_ip or kernel_announce_capabilities, which could be confused with it.

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 the precondition and timing: 'Required before submitting jobs — the gateway needs at least one capability per kernel.' That is genuine when-to-use guidance an agent can act on, though it names no alternative tool or when-not-to-use condition.

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