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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description's job is lighter. It adds valuable context beyond annotations: data source ('FHWA NBI as of June 2023'), no auth required, and public domain licensing. No contradictions found.

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 well-structured: purpose first, then field enumeration, then usage guidance, then data source. The exhaustive field list is a bit long but serves to set expectations about the richness of the record. There is some redundancy with the output schema, but it earns its place by clarifying the tool's comprehensive coverage.

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 straightforward lookup tool with two well-documented parameters and an output schema, the description covers everything an agent needs: identifiers, how to obtain them, data vintage, auth requirements, and licensing. No missing information that would prevent 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?

Schema description coverage is 100%, and both parameters already have detailed descriptions with examples and format patterns. The description adds the semantic context that state_code and structure_number together identify a specific bridge, but does not provide additional syntax or format details beyond the schema. Baseline 3 applies since the schema does the heavy lifting.

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 uses a specific verb ('Retrieve') and names the exact resource ('full NBI record for a specific US highway bridge') along with the two required identifiers. It clearly distinguishes itself from sibling tools like nbi.search and nbi.nearby by indicating this is the record retrieval tool, not a discovery tool.

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?

Explicitly instructs to 'Use nbi.search or nbi.nearby to discover structure numbers before calling this tool,' which is a clear when-to-use directive and points to the correct alternatives. This is exactly what an agent needs to route to the right tool.

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