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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely non-derived context: the 1-credit cost, the 25 calls/day free-tier cap, and the interpretation scale (fuerte/prometedor/mixto/debil). It does not mention error behavior for invalid or non-U.S. tickers.

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 dense sentences with the metric and pillars front-loaded, followed by the level vocabulary and cost. No filler, no repetition of the title, and every clause carries information an agent needs.

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 the return: a 0–100 score plus seven named pillars and their four-level vocabulary. Combined with the credit and rate-limit disclosure, this is sufficient for a single-parameter read tool; only the failure mode for bad tickers is unaddressed.

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?

One required parameter with 100% schema coverage already documents 'ticker' with an example, so the baseline is 4. The description's only addition is scoping to U.S. stocks, which usefully narrows the ticker domain 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?

States a specific resource and metric: the Faro DNA score (0–100) for a U.S. stock, plus its seven named pillars. An agent can tell exactly what comes back. It does not explicitly contrast with the sibling rank_dna, so it stops short of a 5.

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?

Usage is implied by 'of one stock' and the credit cost, but there is no explicit when-to-use or when-not guidance, and no named alternative such as rank_dna for multi-stock comparison. The agent must infer single-ticker scope selection.

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