get_flow_anomalies

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

Annotations already indicate readOnly, idempotent, and non-destructive behavior. The description adds value by detailing duplicate removal, as_of behavior, partial failure handling, and caching policy (partial responses never cached). No contradiction with 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 a single paragraph that efficiently conveys the main purpose, constraints, and behavioral details. It is front-loaded with the core action. Minor improvement would be structuring into bullets, but it is still concise and clear.

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?

Given the presence of an output schema, the description adequately covers inputs, limits, error handling, and relationships. It addresses all key aspects of tool usage without needing to reiterate return values.

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 coverage is 0%, so the description must compensate. It explains 'site_ids' as an array of strings for 1-25 USGS sites and 'as_of' as an optional ISO date. However, it does not specify format constraints or default behavior beyond what is in the schema.

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 purpose: 'Compare current discharge with date normals for 1-25 USGS sites.' It also distinguishes from sibling tools like 'get_flow_anomaly' by specifying multiple sites and adding details about duplicate removal and as_of parameter.

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 provides context for use: it handles multiple sites, removes duplicates, and references the same fields as 'get_flow_anomaly'. It does not explicitly state when to use this tool instead of alternatives, but the mention of 1-25 sites implies it is for batch operations.

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