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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds behavioral context about the prerequisite nature and vintage-dependent layer IDs, which goes beyond annotations. However, it doesn't disclose output format or pagination, but that's minor given 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, front-loaded with the primary purpose, and includes a clear usage directive without redundancy. Every word earns its place.

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 list tool with no output schema, the description provides sufficient context: it enumerates the content, gives the call order, and warns about vintage differences. Annotations cover safety, so nothing essential is missing.

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% for all three parameters, so the baseline is 3. The description doesn't add additional parameter semantics beyond what the schema already provides; it focuses on the output layer_id rather than input details.

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 function: 'List the queryable TIGER/Line geography layers' and enumerates concrete layer types. It explicitly distinguishes itself from tigerweb_query by positioning this as the prerequisite step to obtain layer_id, which differentiates it from the sibling 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?

It explicitly says 'Call this FIRST to get the layer_id that tigerweb_query needs', providing direct when-to-use guidance and sequencing. The warning about vintage differences ('never reuse one from memory') adds important usage context that prevents incorrect reuse.

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