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

Annotations already carry readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses that it returns the approved guide or the latest draft, describes what the owner-facing view contains, and warns that verbose output is "several times larger." It stops short of noting auth/permission requirements or whether drafts are flagged.

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 front-loaded sentences with the verb and default behavior stated first and the verbose caveat last. The long enumerated content list is dense but justified as it tells the agent what to expect in the return. There is minor redundancy between the phrasing of the verbose caveat here and in the schema.

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?

With no output schema, the description correctly carries the burden of describing returns, and it does so by enumerating the guide's sections and the compact-vs-verbose distinction. Nothing critical to invoking the read correctly is missing, though it could note pagination or trimming behavior.

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 100%, so both parameters (including the linked list_brands provenance for brandId) are already documented. The description's verbose explanation (full stored record, ids, provenance, storage refs) largely mirrors the schema's own description, so it adds marginal meaning rather than new semantics. 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 ("Fetches") plus the resource ("a brand's approved (or latest draft) brand guide") and enumerates the contents it returns (identity, voice rules, palette, logo links, etc.). The resource name cleanly separates it from siblings like get_brand_brief, get_strategy, and get_post, so an agent can select it without opening a schema.

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 gives clear guidance on the verbose flag ("Compact by default... rarely needed"), which is genuine conditional usage advice. However, it never says when to reach for this tool versus get_brand_brief or get_strategy, nor states prerequisites. Usage is implied by the resource but not explicitly scoped against alternatives.

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