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

Annotations already disclose readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the tool's scope (every layer), the optional plain-English guide, and the nfhl_query ordering, but it does not describe output size/format or rate limits. This is reasonable but not rich behavioral disclosure beyond the 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?

Two sentences, minimal filler, and the core action is front-loaded. The parenthetical list of relevant layer types is long but purposeful, and the imperative 'Call this before nfhl_query' is a valuable closing instruction.

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 read-only catalog tool with one optional, fully-documented parameter and rich annotations, the description is complete. It covers the returned fields, adds a guide to meaningful layers, and tells the agent when to invoke it relative to nfhl_query.

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%: the filter parameter is already documented as a case-insensitive substring with examples. The description adds no parameter-level meaning, but with full schema coverage, the baseline of 3 is appropriate.

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 opens with a specific verb and resource: 'List every layer in the FEMA National Flood Hazard Layer MapServer' with the exact output fields (id, name, geometry type). It is clearly distinct from sibling tools like nfhl_query and nfhl_flood_zone_at_point, which query data rather than catalog layers.

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 before nfhl_query', giving a clear ordering instruction relative to a sibling tool. It does not fully map out when-not-to-use cases or alternatives such as nfhl_flood_zone_at_point, so it falls just short of the strongest usage guidance.

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