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

While annotations handle safety ('readOnlyHint: true'), the description adds vital behavioral context by detailing the structure and specific data points returned (e.g., 'text series also list their values'), which dictates how an agent must process the result.

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 single sentence is highly efficient, with every phrase contributing to the definition of the tool's behavior and scope without any redundancy.

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 empty input schema and lack of an explicit output schema, the description is maximally complete by fully outlining the data structure and types of information the agent can expect to receive.

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?

With zero input parameters, the parameter semantics are inherently high. The description adds value by defining the expected output structure and content, compensating for the lack of input complexity.

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 action (List) and the resource (series), providing specific output data points like 'type (number or text)', 'point counts', and 'date ranges', which precisely defines its role compared to retrieving a single series.

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 usage is implied by the 'list all' scope; it is the tool of choice for comprehensive overviews. However, it does not explicitly state when to use this tool versus the sibling 'get_series' for targeted lookups.

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