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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds valuable behavioral scope beyond that: models cover only the modelled portion of the account, each contains many entities, and one is the default. It doesn't describe ordering or output shape, but for a read-only list tool this is solid added context.

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?

Front-loaded with the verb and resource, then terminology clarification and the routing note. Every sentence earns its place, though the dbt parenthetical and the closing list_flows pointer add slight length relative to a simple list tool.

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 parameters, no output schema, and safety already in annotations, the description supplies what's needed: what a model is, that only modelled areas appear, and which sibling covers connected-but-unmodelled sources. Nothing required to call it correctly is missing.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description instead characterizes the result set (models, default, coverage), which is the relevant semantic here.

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+resource ('List the semantic models available'), clarifies the domain term by contrasting it with the dbt meaning, and notes what each model contains (one source system, MANY entities) plus which is default. It also distinguishes itself from list_flows, so an agent can tell it apart from siblings without opening schemas.

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 explicit when-to-use ('when you are about to ASK something and need to know which world to ask in') and names the alternative and its purpose ('what the account is connected to is list_flows'). The routing between this tool and its sibling is unambiguous.

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