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

Annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false). The description adds meaningful behavioral constraints beyond that: the own brand cannot be hidden, and suggested brands must be transitioned through the approve/reject tools rather than updated. It does not discuss auth requirements or what happens to unspecified fields.

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 sentences, front-loaded with the mutable field list, followed by the two governing constraints. No filler; every clause carries information an agent needs.

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 10-parameter mutation tool with no output schema, the description covers what can be changed and the two hard constraints. It omits partial-update semantics (whether unlisted fields are left unchanged) and return behavior, which are minor gaps given the idempotent annotation.

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 80% and the schema already documents the parameters in detail (enums, hex pattern, null-clears semantics). The description's field list loosely maps to parameters (aliases→trackedNames, regex matching→useRegex/nameRegex) but adds no syntax or format detail the schema lacks, so the baseline of 3 applies.

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 exactly which fields are mutable (name, aliases, domains, regex matching, status, color), which cleanly separates it from create_brand and delete_brand. It also names approve_suggested_brands/reject_suggested_brands, so the agent can distinguish this from sibling operations on the same resource.

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 clear when-not constraint ('the own brand cannot be hidden') and explicitly routes suggested-brand transitions to approve_suggested_brands / reject_suggested_brands, which is real alternative guidance. It stops short of stating general preconditions (e.g. how to obtain id, partial-update expectations), so it is strong but not fully exhaustive.

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