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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the underlying endpoint (GET /v1/Clients/contractPOs/{clientId}) and a hint at returned fields, but says nothing about pagination, volume, or empty-result behavior for an open-world remote call.

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?

One front-loaded sentence stating the resource, scope, and payload, followed by the endpoint path. No filler, though the endpoint string is of marginal value to an agent compared with the rest.

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?

With no output schema, the description's 'PO numbers and amounts' is the only signal of return shape, and it is thin (no id fields, no list envelope, no pagination). For a simple single-parameter read with annotations this is borderline adequate but leaves gaps an agent must discover at call time.

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% and the sole parameter client_id is documented as 'Bilflo client id.' with a minimum constraint. The description adds no format or sourcing guidance (e.g., where to obtain a client id) beyond the schema, so the 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?

The description names a specific resource (contract purchase orders) scoped to a single client and clarifies the payload (PO numbers and amounts used for billing). It is distinguishable from bilflo_list_job_purchase_orders only by inference from the word 'contract' and the client scoping, not by any explicit contrast.

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?

Usage is implied by the single required client_id and the phrase 'of one client', so an agent can infer this is a per-client lookup. However, it never states when to choose this over bilflo_list_job_purchase_orders or the other client sub-resource listers (agreements, invoice groups), nor any prerequisites.

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