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

Annotations only declare readOnlyHint=true, so the description adds valuable behavioral context: ordering by alertId, pagination with offset/limit and next-offset reporting, and filter matching semantics (full extent, overlap). These are not inferable from annotations or schema. No contradictions. Slightly loses a point for not mentioning anything about error behavior or edge cases, but for a read-only query tool this is adequate.

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 dense sentences, packed with functional details without fluff. It front-loads the primary purpose, then filters, then paging. While it is not minimal, every clause earns its place, and the structure is logical. Slightly long but efficient enough for 4, not quite 5 due to the complexity of information.

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?

The description covers all necessary aspects for an agent to call this tool correctly: what it returns, all filter options with matching behavior, the ability to fetch all alerts, and pagination instructions. Since an output schema exists, return-value details are not needed. Combined with the rich schema, no critical information is missing. This is complete for a search/query 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?

The schema descriptions for all 6 parameters are thorough (100% coverage), providing the baseline of 3. The tool description adds extra meaning: for stateRoute it explains natural forms and the prefix-matching rule, and for startMilepost it explains extent-overlap matching. These clarifications go beyond the schema, raising the score to 4. Some param details (e.g., region list) are already in the schema, but the additions are meaningful.

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 verb 'Returns' and the resource 'active WA highway alerts', listing the alert types (incidents, construction, closures, restrictions). It distinguishes itself from sibling tools, which focus on ferries, tolls, mountain passes, etc., by explicitly targeting highway alerts. No ambiguity about what this tool does.

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 explains when to use it: to search for alerts, with optional filters and paging. It states 'Omit all filters to return all current statewide alerts' and explains paging. It doesn't explicitly mention alternatives or when not to use, but the sibling set is obviously distinct (ferry alerts, border waits, etc.), so the usage context is clear. Lacks explicit 'use when' or 'use instead of' guidance, hence 4.

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