invoiceninja_list_clients

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered by structured data. The description's filter-operator details are useful context but are largely parameter semantics; it says nothing about rate limits, permissions, or what a paginated result set looks like. With annotations carrying the behavioral burden, a 3 is appropriate.

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?

Purpose and the get_client hand-off are front-loaded, and the dense extra_filters block is necessary content rather than filler. The operator enumeration is compact given how many keys it must cover, with only minor redundancy between the header ('filtering, sorting, pagination') and the schema-documented params.

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 9-parameter, zero-required list tool with no output schema, the description covers the one param the schema punts on and implies pagination behavior plus the follow-up call. It never mentions response_format's markdown/json distinction or response shape, but annotations and schema cover enough that nothing critical for invoking the tool is missing.

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 baseline is 3, but the extra_filters parameter's schema explicitly defers to the description ('see the tool description'), and the description delivers the key list plus operator syntax ('gt:0', 'between_balance', 'YYYY-MM-DD,YYYY-MM-DD'). That materially exceeds what the schema alone provides, though other params (sort, fields, status, include, response_format) get no added meaning.

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 first sentence gives a specific verb and resource ('List clients from Invoice Ninja') plus the three capabilities (filtering, sorting, pagination), so an agent can distinguish it from invoiceninja_get_client, invoiceninja_list_invoices and invoiceninja_search without opening any schema.

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 explicitly routes the agent: use invoiceninja_get_client with an id from this list for the full record, which is a clear list-then-fetch workflow. It does not, however, say when to prefer this over invoiceninja_search or how deep pagination should be handled, so it stops short of full when-not guidance.

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