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

Goes well beyond the annotations (readOnly, openWorld, non-idempotent) by disclosing what gets recorded (14 named features plus function-word rates with the author's own range), what persists downstream (every brief carries evidence.voice), and an important non-behavior guardrail ('This is never an AI-detection score'). This is rich, non-obvious context that annotations cannot convey.

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?

Purpose is front-loaded and the sentences are dense with useful specifics rather than filler. It is on the long side and could be trimmed slightly, but nearly every clause carries actionable information.

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 tool with no output schema, it explains the downstream payoff (distance metrics reported by review_writing/score_content_draft) and the input requirements thoroughly. The only modest gap is that it does not describe what create_voice_profile itself returns on the call.

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 the baseline is 3, but the description adds substantive meaning: URL count guidance (6-10, vs the schema's max 25), word-count thresholds, preference for unedited drafts, and the rule to keep one profile per register. This meaningfully augments the schema rather than restating it.

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 and resource — building a 'VOICE FINGERPRINT' from the author's own unedited writing — and names the downstream artifacts (evidence.voice, review_writing, score_content_draft). An agent can distinguish it from siblings like declare_voice, get_voice_profile, and voice_probe without opening any 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?

Gives concrete input guidance (6-10 URLs, 5,000+ words recommended, 2,000 minimum, unedited drafts beat published posts) and an explicit behavioral instruction: 'Ask the user for the samples; do not pick them yourself.' It does not explicitly name alternative sibling tools or state when-not to use it, so it falls short of a 5.

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