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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering safety. The description adds that all facts are published on the public website, indicating reliability and source. It also instructs to call it first, which is useful behavioral guidance beyond the annotations. No contradiction with annotations.

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 two sentences with no wasted words. It front-loads the core purpose and lists specific fact categories, then provides a clear usage directive. It is succinct and easy to parse, earning a top score.

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?

Given the zero-parameter schema and annotations that already cover safety and idempotency, the description is complete. It specifies the exact content of the facts and the source, and even gives a usage hint. The lack of an output schema is mitigated by the explicit enumeration of what the tool returns. No additional information is needed for correct invocation.

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 has zero parameters, so schema description coverage is trivially 100%. The description does not need to explain any parameters. It lists the types of facts returned, which compensates for the lack of an output schema and gives the agent an idea of what to expect. Baseline 4 applies as no parameters exist.

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 the tool's purpose: it retrieves published business facts about 905 Trades, listing specific content types (phone number, hours, services, etc.). It is distinct from siblings like 'fetch' (generic), 'request_quote' (action), and 'search' (query), and the directive 'Call this first' further clarifies its role as the initial information source.

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 explicitly says 'Call this first,' which is a clear usage directive. It also implies that the tool provides foundational facts before other actions. However, it does not explicitly state when not to use it or compare it to alternatives, though the context of a zero-parameter facts tool makes its role obvious.

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