brand_build_personas

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

Despite no annotations, the description discloses key behaviors: it writes to .brand/strategy.yaml, auto-generates persona IDs, bumps a session counter, and indicates typical needed count (3-5). It could mention whether writes are destructive or reversible, but the given details are strong.

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?

Every sentence adds value: purpose, modes, side effects, usage triggers, exclusions. It is front-loaded with the core function and uses efficient, specific language. No wasted words.

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?

Given no output schema, the description includes what is returned ('persona data and total count'). It covers inputs, outputs, side effects, and context (Session 4). It is fully self-contained for an agent to use 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?

The schema already describes all three parameters (100% coverage), but the description adds significant value: it explains the purpose of each mode, the auto-ID generation, and that record mode accepts JSON or freeform text. This goes well beyond the schema.

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?

The description clearly states the tool builds buyer personas via a guided interview, names three modes (interview, record, list), and distinguishes it from the sibling tool brand_compile_messaging. The verb 'build' plus resource 'buyer personas' is specific and informative.

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 explicitly provides trigger phrases ('define personas', 'who is our audience', 'start Session 4') and tells when NOT to use it (for voice, pointing to brand_compile_messaging). This provides clear guidance for tool selection.

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