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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety profile is covered. The description contributes only the clarifying gloss that an 'agreement' means billing terms; it says nothing about result volume, pagination, or what happens when a client has no agreements on file.

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 fragments with zero filler. It is arguably too terse, reading like a docstring fragment rather than guidance, but nothing is wasted.

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 single-parameter read tool with annotations and no output schema, the description is minimally adequate but leaves the return shape (what fields an agreement carries) and empty-result behavior unstated. An agent knows what to call and how, but not what to expect back.

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% and the sole parameter is documented as 'Bilflo client id.' The description's phrase 'for one client' reinforces single-client scoping but adds no format or sourcing detail beyond the schema.

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?

Names the exact resource (agreements, glossed as billing terms) scoped to a single client, which distinguishes it from sibling list tools like bilflo_list_client_contract_pos and bilflo_list_client_invoice_groups. The verb is only implied by the name/title, not stated in the description text.

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 when-to-use guidance, no exclusions, and no pointer to related siblings such as bilflo_get_client or the contract-PO list. An agent must infer selection purely from the tool name and the required client_id.

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