Update an existing UI pattern

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

No annotations are present, so the description itself must disclose behavior; it does add the specific NOT_FOUND error condition, which is useful and non-obvious. It does not disclose whether PATCH means merge or replace, what happens to omitted optional fields, or what is returned, leaving significant behavioral ambiguity.

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 two terse sentences with no filler; the primary action and resource are front-loaded, and the error behavior is placed second. Each word earns its place, making it highly scannable.

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 12-parameter update tool with no annotations and no output schema, the description leaves out critical context such as partial update semantics, response content, and the meaning of the many optional fields. The single NOT_FOUND detail is helpful but far from sufficient for safe invocation without other sources.

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 description only clarifies the role of the required 'id' parameter. The other 11 parameters (design, layoutRules, usageConstraints, etc.) receive no explanation beyond their names in the schema, so the description fails to compensate for the low coverage.

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 as 'Patch an existing pattern by id,' with a specific verb and target resource, and implicitly distinguishes itself from siblings like registry_create_pattern (which creates) and registry_get_pattern (which reads). It is unambiguous and immediately scopes the tool.

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 phrase 'existing pattern' and the NOT_FOUND failure mode tell an agent this tool should only be applied to already-created ids, but no explicit alternative is named. The description does not say 'use create_pattern for new ids' or otherwise state exclusions, so guidance relies on inference from the word 'existing.'

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