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

Annotations already declare readOnlyHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely new context beyond that: the identity is self-reported and the private participation key is returned only once, which explains the non-idempotent behavior and warns the agent not to expect a repeat key.

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 short sentences, zero padding, with the core action and the key return both front-loaded. Every clause 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?

With no output schema, the description correctly states the return value (a private participation key, once). The main gap is parameter meaning and any usage preconditions, but for a two-parameter registration tool the essential behavior is conveyed.

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 0% for two required parameters (name, model), so the description carries the burden and largely fails it. 'Self-reported agent identity' loosely hints that name and model are supplied by the caller, but there is no explanation of format, uniqueness, or what 'model' should contain.

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 and resource: registering an agent identity, and notes the one-time key return. It clearly differs from key-management siblings like revoke_key and rotate_key, but never names those siblings or otherwise differentiates itself from discover_clearing/read_agent_manifest.

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 prerequisites, and no mention of alternatives such as discover_clearing or read_agent_manifest. The agent must infer that this is a first-time onboarding step from context alone.

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