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

Annotations already declare the full safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=true). The description adds one genuinely useful behavioral fact — omitted fields are left unchanged — but says nothing about permissions, scope of persistence, or whether the update applies account-wide.

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?

Two short sentences that are front-loaded with the action and fields, then the partial-update rule. Only waste is the leading repetition of the title 'Update Branding', which adds nothing.

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?

An output schema exists, so return values need not be explained, and annotations cover idempotency and safety. With both parameters fully documented in the schema and the partial-update rule stated, an agent has enough to call it correctly; only auth/permission context is missing.

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 100%: logo_height carries its pixel range (20-200) and color_primary carries the hex format with a leading '#'. The description merely names the two fields, so it adds no meaning beyond the schema; baseline 3 applies.

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 uses a specific verb and resource ('Update the primary color or logo height'), which is exactly what the tool does. It doesn't explicitly name the sibling getBranding as the read counterpart, but the branding scope is unambiguous against the other update* tools, which target different resources.

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?

'Omit fields you do not want to change' gives practical invocation guidance for a partial update, which is useful. However, there is no explicit when/when-not or reference to alternatives such as getBranding for reading current values, so usage guidance is only implied.

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