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

Annotations declare this is a mutation (readOnlyHint=false) but not destructive, and the description adds a genuinely non-obvious behavioral trait: 'Never overwrites a brief you've hand-edited.' That protects the agent from assuming a clobber, which annotations alone do not convey. It does not cover idempotency or the no-guide-exists case.

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?

Front-loaded with the action and resource; the long parenthetical definition of the brief earns its place by grounding an otherwise jargon term. Three sentences, all load-bearing, though the parenthetical is dense enough to slow reading.

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 one-parameter mutation with no output schema, the description covers purpose, trigger context, and the hand-edit safeguard adequately. Return behavior and failure modes are left implicit, which is the only meaningful gap.

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 100% and the single brandId parameter is fully documented in the schema (including provenance from list_brands), so the description adds no parameter meaning. Baseline 3 for a high-coverage schema where the schema does the heavy lifting.

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?

Uses a specific verb (regenerates) plus a precisely scoped resource (the brand's knowledge brief), and even defines what that brief contains. It is clearly distinguishable from get_brand_brief (retrieval) and generate_brand_guide (guide creation) without opening either 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?

Explicitly states the default behavior ('Runs automatically on every guide approval') and the condition that selects this tool ('use this for an on-demand re-run'), which is exactly the when-to-use guidance an agent needs. It stops short of naming sibling alternatives, but the routing condition is unambiguous.

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