Update an existing design token

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

The description discloses one useful failure behavior: it fails with NOT_FOUND if the id does not exist. However, there are no annotations, so the description carries the full burden; it does not mention side effects, partial vs. full update semantics, immutability of fields, permissions, or return value behavior. This is minimal coverage for a mutation tool.

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?

The description is tight and front-loaded: two sentences, no filler. The core requirement and a key failure mode are stated efficiently. It is concise, though it sacrifices substantive guidance that would be more valuable than additional prose.

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 the tool's complexity (11 parameters, nested objects, no annotations, no output schema), this description is incomplete. An agent has no way to understand how to populate most fields, what the update response looks like, or what constraints apply beyond the id. It covers only the most basic invocation scenario.

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%, and the tool has 11 parameters, yet the description only references the id parameter. None of the other fields (name, type, usage, value, aliases, category, deprecated, deprecation, description) are explained, and the nested deprecation object and heterogeneous value type remain entirely undocumented in both the schema and description.

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 clearly states the operation: 'Patch an existing token by id.' This identifies the verb, resource, and scope, and distinguishes it from create/get operations by the word 'existing.' It does not explicitly name sibling alternatives, but the meaning is unambiguous.

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?

Usage is implied: use this tool to modify an existing token by id, rather than to create or read a token. However, there is no explicit guidance about when to choose this over registry_create_token or registry_get_token, and no mention of whether this is the only way to update token metadata.

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