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

Annotations already declare readOnly/destructive/openWorld hints, so safety is covered. The description goes further and explains the response shape (agentType, customer, instanceCount) and the 'Role families' rollup triggered when instanceCount > 1, which is real behavioral context since no output schema exists.

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?

Three sentences, front-loaded with the core action, then response semantics. The detail about instanceCount and the rollup earns its place given there is no output schema, though it could be tightened.

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 tool with no output schema, the description usefully documents the returned fields and the multi-instance rollup. It omits any mention of pagination despite the limit parameter, a minor gap.

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 limit, customerId, and includeVariants are already documented in the schema. The description adds nothing about these parameters, so baseline 3 applies.

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?

States a specific verb+resource ('List all agents') scoped to the authenticated customer. It does not explicitly distinguish itself from the singular get_agent sibling, but the plural 'all' and the customer scoping make the intent clear enough.

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?

No guidance on when to use this vs get_agent or the many other list_* siblings, and no stated prerequisites or exclusions. The 'authenticated customer' scoping is context, not usage direction.

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