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

Annotations already declare non-readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuine behavioral context beyond them: the own-brand hiding restriction and the fact that suggested brands must be transitioned through approve/reject tools rather than this one.

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 tight sentences with no filler; the field list comes first and the routing constraints are front-loaded immediately after. Every clause carries information.

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 tool with no output schema, the description supplies the mutable-field set and the key usage constraints, and annotations cover safety. Minor gaps remain (partial-update semantics, whether omitted fields are preserved), but nothing critical is missing.

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 78%, so the schema already documents most parameters (including null-clears semantics and the hex-color note). The description's field list roughly mirrors the schema without adding format or constraint detail, so baseline 3 is appropriate.

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 (brand) and enumerates the mutable fields (name, aliases, domains, regex matching, status, color), letting an agent distinguish it from create_brand, delete_brand, and get_brand. It does not, however, explicitly name update-siblings it might be confused with, so it stops short of a 5.

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 concrete when/when-not guidance: 'The own brand cannot be hidden' and 'Suggested brands transition only via approve_suggested_brands / reject_suggested_brands', which routes the agent away from this tool for suggestion workflows. It covers exclusions well but does not describe general preconditions (e.g. needing the brand to exist or workspace scoping).

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