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

Annotations already declare destructiveHint=true, non-read-only and non-idempotent, so the safety profile is covered. The description goes beyond them by disclosing blast radius ('applies the brand to every hosted help center and widget at once'), patch semantics, and input format constraints (six-digit hex, absolute image URLs). It stops short of permissions, reversibility, and what the response contains.

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 tight sentences, each earning its place: patch semantics first, then blast radius, then format rules. Nothing is restated and nothing is padded.

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, workspace-wide mutation with 9 optional nested params and no output schema, the description covers the two things an agent could not infer (scope of effect and input formats) but omits permission requirements, reversibility, and what the call returns. Adequate to invoke, not complete for the risk level.

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 11% across 9 params, so the description must carry the load and it partly does: hex format for colors and absolute-URL format for images are genuinely additive. But the nested structures (logo, fonts, button, footer social list) receive no explanation in either schema or description, leaving the majority of parameters undocumented.

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?

Specific verb ('Change parts of') plus specific resource ('the brand kit'), and the patch semantics ("anything left out stays") make the tool's behaviour unambiguous to any agent. It does not name a sibling, so an agent must infer the complement of get_brand and import_brand_from_website 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?

The description implies usage ('change parts', omitted fields untouched), which is enough to know this is the partial-update path rather than a full replace. It never states when not to use it, nor points at import_brand_from_website for bootstrapping a brand from a site, so routing among brand tools is left to inference.

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