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

Annotations already establish this as a non-destructive, non-read-only mutation (readOnlyHint=false, destructiveHint=false). Beyond that, the description adds real behavioral detail: key-wise merge semantics, explicit-null deletion, rejection of unknown keys and invalid values, and the rule that colours must be nested under config_patch.theme. That goes well past what the annotations disclose.

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 core action is front-loaded into the first clause, followed by compact, high-value rules for config_patch and widget theming. It is dense but efficient; the widget-specific example is justified because it prevents malformed requests.

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 four-parameter nested-object mutation with no output schema, the description covers the critical gaps: merge behavior, null deletion, validation refusal, and widget theme nesting. Safety is covered by annotations. What is missing is minor, such as whether the call is idempotent or what the response contains, but the description is sufficiently complete to call the tool correctly.

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 baseline is 3. The description nevertheless adds meaning beyond the schema by explaining that config_patch is merged key-wise and that a null value deletes a key, plus detailed guidance on where widget colours must live. These are semantic constraints the schema alone does not convey.

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?

Opens with a specific verb and resource: 'Patch a deployment's name/description/config.' The updatable fields are named, so an agent can distinguish it from create_deployment, update_agent, and probe_deployment 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 clear operational context: config_patch merges key-wise, and for the web widget it points to get_widget_settings for the setting list. It does not explicitly state when to prefer this over a sibling such as update_agent or create_deployment, so it stops short of full when/when-not guidance.

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