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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new context: the response is an aggregate (debt per currency, open-order counts) and the call is free. It doesn't explain archived-supplier handling or whether search is partial/case-insensitive, but against annotations carrying the safety profile this adds solid value.

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 tight sentences with the resource front-loaded, followed by search scope and a one-word cost note. No filler; every sentence conveys usable information.

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?

No output schema exists, so describing the return content is the description's job and it does so well; the safety profile is covered by annotations. The gap is the undocumented include_archived flag and absence of any pagination note, which keeps this from a 5 for a two-parameter listing tool.

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 0%, so the description must compensate. It clarifies the 'search' parameter's scope (name, contact or email), which the schema does not, but the 'include_archived' parameter is never mentioned, leaving half the parameters undocumented in both places.

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 ('Suppliers by name', title 'List suppliers') and goes further by describing exactly what each row carries: owed amounts on open bills per currency plus open-order counts. This is distinct from siblings like purchasing_list_bills or purchasing_list_orders without needing to open 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?

Implies the search behavior ('Search by name, contact or email') and adds a cost hint ('Free'), but never says when to reach for this versus other purchasing listing tools, nor any prerequisites. Guidance is present but only at the level of how to filter, not when to choose it.

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