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

Adds real context beyond the annotations: the operation is PATCH-style partial update, null explicitly clears a nullable field, and it costs no credits. This meaningfully reframes destructiveHint=true as 'nullable-field clearing' rather than wholesale record replacement. It still doesn't disclose error behavior or whether clearing is reversible.

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 short sentences, zero filler, with the core update semantics front-loaded before the null-clearing detail and the cost note. Every sentence earns its place.

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 an 11-param mutation with no output schema and sparse schema descriptions, the definition covers the essential ambiguities: partial update semantics, null-clearing, and cost. Remaining gaps (validation failures, response shape) are minor given there is no output schema to reference.

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 9%, so the description must compensate, and it does for the highest-ambiguity aspect: the many anyOf[string, null] params, by explaining that null clears a field and unchanged fields should be omitted. Individual field meanings are self-evident from their names, but no per-field detail is offered for things like appDemo vs appDemos.

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 and resource ('Update fields on an existing brand'), which clearly separates it from create_brand, delete_brand, and get_brand in the sibling list. It doesn't explicitly name a sibling to route against, but the CRUD verb disambiguates on its own.

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 invocation guidance — 'pass only the fields that change' — but never states when to reach for this tool versus alternatives such as update_influencer or update_managed_account. Usage is implied by the brand resource rather than spelled out.

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