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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=false, so the safety profile is largely covered. The description adds a genuine boundary disclosure (no delete exposed over MCP) that annotations do not convey. However, it never explains what makes this update destructive or whether omitted fields are overwritten, leaving the most consequential behavior undisclosed.

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 with no filler, and the core action is front-loaded. The second sentence is a useful scope note rather than padding, though the overall body is arguably too terse to be ideal for a 5-parameter mutation tool.

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 destructive, non-idempotent mutation with five parameters, 20% schema coverage, and no output schema, the description omits which fields are editable, whether the update is partial or full-replace, authorization needs, and return behavior. The delete-boundary note helps but does not close the gap.

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 only 20% (just brand_id), and the description names none of the updatable fields (name, voice, guidelines, value_proposition). With low coverage the description is expected to compensate, and it does not, so an agent must infer the writable surface from the raw schema alone.

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?

States a specific verb (Update) and resource (fields on one owned brand identity), which clearly separates it from create_marketing_brand and get_marketing_brand. It stops short of naming siblings or the list tool needed to source brand_id, so it is clear but not fully differentiated.

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?

"No delete is exposed over MCP" implies a capability boundary, and "one owned brand identity" implies single-record scope, so usage is inferable. There is no explicit when-to-use guidance, no reference to list_marketing_brands for obtaining the UUID, and no stated prerequisites.

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