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's only job is to add context — and it adds none. It says nothing about pagination behavior (despite start/next_start semantics in the schema), maximum result sizes, or what a list reply looks like, though those details live in the schema rather than the prose.

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 compact fragments with no filler, and the resource identity plus returned fields are front-loaded. It is arguably under-specified rather than padded, which is a completeness problem more than a conciseness one.

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 an 11-parameter read tool with no output schema, the description at least enumerates the fields a person row carries, which partially compensates for the missing return documentation. However, it omits pagination behavior, filter semantics and sibling routing, leaving meaningful gaps for a tool of this surface area.

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% across all 11 parameters, so the schema itself fully documents sort, dir, limit, query, start, filter and the only_* flags. The description adds no parameter meaning beyond that, so the baseline 3 for high-coverage schemas is correct.

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 names the resource and its subtypes precisely ('Customers, vendors, employees and other contacts') and even lists the fields carried (name, company, number, roles, addresses), so an agent knows what this list contains. It lacks an explicit verb, but the GET /person/list.json endpoint and the naming pattern versus get_person make the list-vs-get distinction inferable rather than stated.

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?

There is no guidance on when to use this tool versus the obvious alternative cashctrl_get_person for a single record, nor when to use the only_customers/only_vendors/only_employees/category_id narrowing options. The agent must infer usage entirely from the name and schema.

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