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

With no annotations, the description carries the full burden, and it leaves the most important behavioral question unanswered: is this a partial patch or a full replace of the kit body? It says nothing about whether omitted fields are cleared, what permissions/plan requirements apply, or what happens to assets referenced by the kit.

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 padding, and the identifying verb+resource lead. The second sentence is efficient shorthand, though it offloads explanation to a sibling schema rather than delivering it here.

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 9-parameter mutation with nested objects, no annotations and no output schema, the definition is far too thin. An agent cannot determine update semantics (partial vs full), field meanings, or the result of the call without opening create_brand_kit's schema and guessing.

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 0% across 9 parameters, so the description must compensate and largely does not. It conveys only that brand_id is the identifier and that all other fields mirror create_brand_kit, leaving gradeBias, voiceTone, enforcement, forbiddenColors and the nested fonts/palette objects completely undefined.

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 an existing brand profile by id'), which distinguishes it from create_brand_kit, get_brand_kit and delete_brand_kit. Minor friction: it calls the resource a 'brand profile' while the tool and siblings call it a 'brand kit', and it never says what aspects are updatable.

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 word 'existing' implies this is for modifying a kit that already exists, so the create-vs-update boundary is implicitly covered. However, it gives no prerequisites (does the agent need to call get_brand_kit first?), no exclusions, and no guidance on when to prefer create_brand_kit.

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