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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true and openWorldHint=true. The description adds real behavioral context beyond them: partial-update semantics (unspecified fields are untouched) and the concrete destructive consequence of is_active=false deactivating the client, which explains why destructiveHint is true. It doesn't cover permission requirements or failure modes.

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 short sentences, front-loaded with a 'WRITE:' marker and the partial-update rule before the field list and endpoint. 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 mutation tool with no output schema, the description plus annotations cover the essentials: partial semantics, the destructive deactivation path, and the endpoint. Missing only peripheral details like error behavior or permission prerequisites.

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 only 33%, so the description carries weight here and does: it enumerates all five writable fields (business name, client code, phone, fax, active flag) and explains that is_active=false deactivates while true reactivates. Length/format constraints remain schema-only, which is fine.

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 (partial update), the resource (client), the exact settable fields, and even the underlying PATCH endpoint. The 'changes only the fields you pass; the rest stay as they are' phrasing cleanly separates it from create/replace-style siblings.

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?

Makes the use case clear: partial modification of an existing client, including the deactivation path via is_active=false. It does not explicitly name alternatives (e.g., use bilflo_create_client for new clients) or state when not to use it, so it stops short of a 5.

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