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

Annotations already declare readOnlyHint=true, lowering the bar. The description adds context that customers map to the accounts model and the endpoint, but it does not disclose behavioral details like pagination defaults, rate limits, or return format beyond what the schema and annotations already convey.

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 concise sentences with no unnecessary words. It front-loads the core purpose and adds a single valuable clarifying detail about the endpoint and capabilities.

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 read-only list operation with a fully documented schema and no output schema, the description is sufficient. It provides the endpoint and model mapping, and the parameters are self-explanatory. It could be more complete by describing the return shape or pagination behavior, but it's strong overall.

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%, so the schema fully documents all six parameters. The description merely states generic capabilities (filtering, sorting, search, expansion) without adding any syntax or semantics not already present 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 it lists customers and explicitly maps to GET /accounts, distinguishing it from the singular get_customer and other list_* sibling tools. The verb 'list' plus the resource 'customers' is specific and unambiguous.

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 provides clear context by describing the underlying endpoint and capabilities (filtering, sorting, search, expansion), which implies when to use it. However, it does not explicitly name alternatives or state when not to use it, such as pointing to get_customer for a single record.

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