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

The readOnlyHint=true and openWorldHint=false annotations already establish that this is a safe, closed-domain read. The description adds value by disclosing the exact payload contents the agent will receive, including credit line and data year, but says nothing about what happens for a missing or invalid plate number.

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?

It is a single front-loaded sentence that opens with the scope ('One plate in full') and then lists the returned fields. The enumerated field list is long but each item is meaningful; the only cost is that it reads as a run-on list rather than structured lines.

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 simple one-parameter read tool with annotations covering the safety profile and a schema documenting the ID, the description is nearly complete: it fully answers what the agent gets back despite no output schema existing. Only error/missing-plate behavior and routing against siblings remain unstated.

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%, with the single 'id' parameter documented as a plate number such as "037", so the schema already carries the parameter semantics. The description adds no format, normalization, or lookup behavior beyond what the schema states, which is the expected baseline for a one-parameter tool.

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 names a specific verb and resource: retrieve one plate 'in full', and enumerates the fields returned (title, subtitle, takeaways, data table, source, claim types, links, credit line). It is clearly distinguishable from siblings like latest_plates or search_plates, which are plural/query tools, although the description never explicitly contrasts them.

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 only implied: the description says it returns 'one plate in full', which suggests use when complete detail for a known plate is needed, but there is no explicit when-to-use statement, no exclusion, and no reference to the alternative siblings (search_plates, latest_plates, get_story) for lookup or listing.

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