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

Annotations already declare readOnly=false, destructive=false, idempotent=false, and openWorld=false. The description adds "controlled" (authorization context) and "supplied" fields (partial-update semantics), but does not explain control_token requirements, null handling, or what happens to unchanged fields.

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?

It is one front-loaded sentence with no filler, but its brevity contributes to under-specification rather than being optimally informative.

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?

The output schema and annotations carry return and safety information, but with 0% parameter coverage and a mutation requiring control_token plus at least one field, the description leaves key invocation context to the schema. It is minimally adequate but incomplete.

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 six parameters. The description vaguely refers to "supplied expressive fields" and a "controlled" identity but never names name/symbol/motto/description, identity_id, or control_token, nor does it explain the anyOf requirement that at least one expressive field be supplied.

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 verb "Update" and resource "expressive fields on a controlled Garden identity" make the operation identifiable and implicitly distinguish it from identity_create/get/delete siblings. However, it does not explicitly name alternatives or clarify the scope of "expressive fields" beyond 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?

No explicit when/when-not guidance or alternatives are provided. "Controlled" hints at ownership or control_token, but the description does not say to use identity_create for new identities or identity_get for reads.

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