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

Annotations already establish readOnly/non-destructive/non-openWorld, so the bar is low, and the description still adds real behavior: the kit=false sentinel, its meaning as the neutral default, and the consequence that the brand flow is inapplicable. It does not explain how brandId and projectId are resolved when both or neither are supplied.

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, front-loaded with what the tool returns, followed by the conditional return semantics. Slightly compressed phrasing ('DNA notes', parenthetical aside) but no wasted text.

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?

There is no output schema, and the description does the most valuable thing it can by explaining the kit=false discriminator on the response. However, for a two-parameter lookup with an undocumented brandId and an unspecified brandId-vs-projectId precedence, it leaves a real invocation ambiguity unresolved.

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 only 50% — projectId is documented, brandId is a bare string with no description. The description does not mention either parameter, so it does not compensate for the gap; an agent gets no guidance on whether brandId overrides the project's own brand or what happens with neither provided.

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 resource (the project's brand kit) and enumerates what it contains (colours, fonts, logo, voice, DNA notes), plus the overlay relationship. It is clearly a read of brand data, distinguishable from list_brands/save_brand/delete_brand, though it never explicitly contrasts itself with those siblings.

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 a concrete when-to-use trigger: 'Read this before designing graphics or writing copy.' It also tells the agent what to conclude when kit=false (the brand flow doesn't apply). No exclusion or named alternative (e.g. list_brands for enumerating kits, get_playbook for style guidance) is offered.

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