Customers List Accessible Customers

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

Annotations declare readOnlyHint=true, which aligns with the description's read-only nature. The description adds value beyond annotations by noting that it returns only directly accessible customershare, implying a permission filter, and that the output is a list of IDs (though this is also in the output schema). It does not contradict 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 concise, with a brief purpose statement and a usage hint, followed by a return type section. It is front-loaded with the key action and avoids unnecessary detail.

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 parameterless tool with a simple output (a list of strings), the description is fully sufficient. It explains what the tool does, when to use it, and what it returns. The output schema already documents the return type, so no additional return detail is needed.

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?

The tool has zero parameters, so there is no parameter semantics to clarify. The description correctly focuses on the output and usage context, which is appropriate for a parameterless tool.

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 it returns IDs of customers directly accessible by the authenticated user, with a specific verb ('Returns') and resource ('customers'). It is distinct from siblings like search_search and metadata_get_resource_metadata, as it lists customer IDs rather than performing search or fetching metadata.

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 explicitly tells the agent to use this tool first to discover customer IDs if the user hasn't provided one, and notes that most other tools require a valid customer ID. It does not explicitly mention when not to use it or name alternatives, but the guidance is clear enough for this context.

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