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

With no annotations, the description must disclose behavioral traits. It reveals the mutation (append or create) and the admin token requirement. It does not cover failure modes or idempotency, but the core side effect is transparent.

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 concise sentences with the most critical info (reservation, token requirement) front-loaded. No wasted words.

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?

The description is inadequate for a 7-parameter tool with no annotations or output schema. It doesn't explain how to specify the client (which of the three client fields), how quantity works, or what the response looks like. An agent would struggle to call it correctly without additional documentation.

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 14%, so the description must compensate by explaining parameters. It does not explain client_id, client_name, client_email, quantity, or auth_token. The only hint is the word 'client' and 'token d'administration', but it fails to map these to specific parameters or clarify which are required for client identification.

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 clearly states the tool appends a line to an existing Qonto draft or creates the draft if absent, and distinguishes it from finalization via qonto_finalize_invoice. The specific verb 'ajoute' and resource 'ligne à un brouillon' make the purpose unmistakable and distinct from sibling tools.

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?

The description provides a concrete usage scenario (recurring clients like Antinote, DKO) and points to the complementary finalize tool. It does not explicitly state when not to use it, but the context is clear enough. The admin token requirement is also mentioned, giving a prerequisite.

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