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

Annotations already signal read-only, idempotent, and non-destructive behavior abstractly. The description adds concrete side-effect boundaries ('does not execute purchases'), pricing ('$0.002 USD per call'), and an optional telemetry enrichment behavior, which goes beyond what annotations alone 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?

The description is compact and front-loaded: it states the core purpose in the first sentence, then quickly covers ranking behavior, exclusions, and pricing. Every sentence adds distinct value without unnecessary elaboration.

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 0% schema coveragehol and no output schema, the description leaves significant gaps: the offer object shape is unspecified, the protocol parameter is unexplained, and the return value is not described. The read-only and pricing context helps, but an agent still lacks enough information to call this correctly without external knowledge.

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%, so the description must compensate, but it only explains the high-level concept of 'caller-supplied offers' and ranking criteria. It does not clarify the structure of each offer, the meaning of 'protocol', or the exact role of max_price_usd and min_reliability beyond loose inference from the ranking criteria.

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 a specific verb and resource: it 'ranks caller-supplied offers' by named criteria (price, reliability, latency, trust). It also distinguishes itself from purchase-executing tools by explicitly saying it does not execute purchases, which helps differentiate it among the many routing/control siblings.

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 implies usage for offer ranking and says it does not execute purchases or provide legal advice, which gives some boundary. However, it does not explicitly state when to use this tool over sibling alternatives like selection_routing_router_* or procurement_policy_control, nor does it mention prerequisites or integration context.

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