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

Annotations declare the safety profile (destructiveHint=true, non-idempotent, not open-world), and the description adds genuinely useful behavior beyond that: partial-update semantics ('only the provided fields are changed'), the identity type being immutable, and fields becoming read-only once used by active DIDs or verifications. It stops short of describing response or rollback behavior.

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?

Dense but well-structured; the core purpose is front-loaded, then usage, then change/immutability constraints, then the read-only caveat. Every clause carries information, though the single em-dash cluster makes it slightly heavy.

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 13-parameter mutation tool with annotations and no output schema, the description covers partial-update semantics, immutability, and the read-only-after-use constraint well. It does not explain error/validation behavior or what the response returns, a minor gap.

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 coverage is 100%, so the schema already documents all 13 parameters (baseline 3). The description adds value by cross-referencing that field semantics match create_identity and by surfacing the fields commonly required (birth_date, id_number, country of tax residence).

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 (update an existing regulation identity of the authenticated customer) and distinguishes it from siblings by naming create_identity, list_requirements and list_identities. An agent can tell it apart from create/delete identity without opening the schema.

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?

Gives a clear triggering context: use it to fill mandatory fields a requirement demands before an address/emergency verification, and points to list_requirements. It lacks an explicit when-not-to-use statement or a direct routing to create_identity, but the usage situation is well defined.

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