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

readOnlyHint=true already tells the agent this is a safe read, so the description only adds the account-wide scope and the HTTP endpoint as corroboration. It says nothing about pagination behavior, default page size, or ordering — relevant for a list endpoint, though the cursor param hints at it.

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?

Two short, front-loaded sentences with no padding. The second sentence restates what the readOnlyHint annotation already implies, so it is mildly redundant rather than wasteful.

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 simple, fully-documented, zero-required-param list tool with safety annotations and no output schema, the description covers what is needed to invoke it. Only pagination/ordering behavior is left unstated.

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 100%, so both limit (1–100, default 20) and cursor are fully documented in the schema. The description adds no format or semantics beyond that, which is the correct baseline when the schema does the heavy lifting.

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 and resource ("List customers in the Orb account") and pins the underlying endpoint (GET /customers). The 'List' verb distinguishes it implicitly from read-one siblings like orb_get_customer and from the write sibling orb_create_customer, though it never names them.

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 list vs get vs get_customer_by_external_id, no prerequisites, and no mention of pagination traversal strategy. The agent must infer usage entirely from the name.

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