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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context by stating the return shape (title, quick answer, derate.app URL), which matters since no output schema exists.

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 the return payload, in two tight sentences. The bilingual duplicate roughly doubles length for no informational gain, though it is defensible for a lang-parameterized 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 output schema, the description correctly compensates by naming what is returned (title, quick answer, URL). The remaining gap is disambiguation from get_guide, which an agent could plausibly confuse with this tool.

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 both query and lang are fully documented in the schema, making 3 the baseline. The topic list ('derate, DEF, emissions, recalls, enforcement, market') loosely hints at query scope but adds no syntax or format guidance beyond the schema's own examples.

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 ('Search DERATE's truck-driver guides and trucking news') and enumerates the covered topics (derate, DEF, emissions, recalls, enforcement, market). It is distinguishable from fault-code siblings, but it does not clarify its relationship to the near-neighbor get_guide (search vs. fetch-a-specific-guide).

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 — search when you don't already have a specific guide or code — but the description never states when to use this instead of get_guide, explain_fault_code, or search_fault_code_library. No exclusions or prerequisites are given, so the agent must infer routing.

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