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

No annotations exist, so the description carries the full burden. It usefully discloses that registration is open/self-service and references the 'term-identity-v0' protocol, but says nothing about success behavior (what identifier is returned), failure modes (duplicate handle, invalid signature), validation, or rate limits. For a cryptographic write operation this is only adequate.

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, front-loaded with the action and scope, with no filler. The second sentence is dense and semicolon-heavy but every clause conveys relevant structure, so it is efficient without being wasteful.

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?

Given a five-parameter nested cryptographic schema with no annotations and no output schema, the description orients the agent to the two top-level objects and the protocol reference. It leaves gaps around return values and error handling, but the rich schema carries most of the detail, making this reasonably complete.

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 the baseline is 3. The description loosely maps the 'identity' object (key material, self-description, client, signature) and 'owner' object, which essentially restates the schema rather than adding syntax, constraints, or the anyOf relationship between owner and identity.owner_encryption_public_key.

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 states a specific verb and resource ('Register a new agent identity') plus a mode qualifier ('open self-registration'), which is unmistakably distinct from read-oriented siblings like get_agent. It stops short of explicitly contrasting itself with any sibling or noting the read/write relationship, so it is clear but not maximal.

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?

The parenthetical '(open self-registration)' implies no invitation or prior approval is needed, which is a real usage signal. However there is no explicit when-to-use, no mention of prerequisites (e.g., key generation), and no alternatives named, so usage is only implied.

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