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

The annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the bar is lower. The description adds genuine behavioral context beyond the annotations by disclosing partial-update semantics — "Pass only the fields you want to change" implies unspecified fields are preserved, which is important for safe mutation. It does not add details on auth requirements or response behavior, but the partial-update trait is the most valuable disclosure here.

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?

Three sentences with zero waste: purpose is front-loaded, field scope in the second sentence, and actionable usage guidance in the third. Every sentence earns its place and the flow is logical — what, what-fields, how-to-use.

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 7-parameter, all-optional mutation tool with annotations covering the safety profile and no output schema, the description covers the essentials: purpose, field scope, partial-update behavior, and pre-check routing. The only meaningful gap is the absence of any statement about return values or confirmation behavior, but for a non-destructive partial update this is a minor omission.

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 86%, above the 80% baseline, so the schema carries most parameter documentation. The description compensates for the one undocumented parameter by naming "voice guide text" (mapping to voiceGuide) and groups the color params and style params into families, adding organizational meaning beyond the schema's individual descriptions. It does not add per-parameter syntax details, but the grouping and coverage of the gap warrant above-baseline credit.

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 states a specific verb and resource: "Updates the brand identity for a workspace's default account voice," then enumerates the updatable content (voice guide text, colors, font style, style descriptors). It differentiates from siblings by scoping to the "default account voice," but it never explicitly distinguishes itself from the similarly named sibling campaignstack_update_workspace_branding, so it falls just short of full sibling differentiation.

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 description gives clear operational guidance: "Pass only the fields you want to change" establishes partial-update conventions, and "Use campaignstack_get_workspace_voice to check current values first" explicitly routes the agent to a read-before-write workflow with a named sibling. However, it lacks any when-not-to-use guidance or explicit alternatives beyond the pre-check tool, so exclusions are absent.

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