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

Annotations already declare this is a non-read-only, non-destructive write. The description adds the clearing semantics (empty string wipes the notes) which is behavior beyond the annotations and clarifies a potential edge case. It doesn't say whether existing instructions are overwritten, what permissions are needed, or the 2000-char limit's implications.

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 short sentences, front-loaded with the core action and followed immediately by the one non-obvious rule. Nothing is padded or wasted.

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 mutation tool with 5 required ID parameters at 0% schema coverage and no output schema, the description is too thin. It never explains the project/site/plan/brief ID hierarchy or where those identifiers come from, which an agent needs to invoke this correctly.

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 0% across 5 required parameters, so the schema carries no semantics. The description only implicitly covers the 'instructions' parameter and hints at 'one article brief' (briefId), leaving projectId, siteId, and planId entirely undocumented in both schema and description.

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 (Set) plus resource (the notes/instructions a writer follows for one article brief), and it clarifies what 'instructions' means in practice. It doesn't explicitly distinguish itself from siblings like update_content_brief_keyword or reschedule_content_brief, but the resource is unambiguous.

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 one concrete operational rule — send an empty string to clear the notes — which is genuinely useful usage guidance. It offers no when-to-use context or comparison against sibling brief-mutation tools, so it stays at implied usage.

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