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

Annotations already cover read-only, idempotent, non-destructive and open-world traits, so the bar is lower; the description adds genuinely new context by flagging the operation as 'paid' and 'multi-domain' and disclosing that it internally reuses map_registrar_products per domain, which implies cost and latency scaling. It does not quantify that cost or mention limits, keeping it out of the top band.

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?

Three tight sentences: purpose and ranking metric first, cost/composition second, sibling differentiation last. No filler and the key constraint ('paid') is front-loaded.

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 still conveys the output shape (leads ranked by product-gap value × severity) and there is a format parameter for verbosity. Minor gaps remain around what a lead record contains and the size of the ranked result, but an agent has enough to invoke it 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 100%, so the baseline is 3. The description reinforces the relationship between the 'brand' seed (portfolio discovery plus ownership buckets) and the explicit 'domains' set, but adds little syntax, default or format detail 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?

Specific verb (rank) and resource (brand portfolio into prioritized registrar-partner sales leads) with the ranking criterion stated (product-gap value × severity). It explicitly distinguishes itself from two siblings, map_registrar_products and batch_scan.

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?

Names the two closest alternatives and the axes on which they differ (per-domain product mapping vs raw scores vs ranked leads), which lets an agent choose correctly. It stops short of an explicit 'use this when / do not use this when' trigger, but the routing signal is strong.

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