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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered elsewhere. The description contributes the authentication/connection requirement and the fact that any operation kind is accepted, which is genuine added context. It says nothing about failure behavior for an invalid reference or about the shape of the returned detail.

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 sentences, no filler, with the core action first and the reference formats second. The parenthetical about first-time connection sits awkwardly inside the opening sentence but does earn its place by flagging auth.

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 one-parameter read tool with full annotation coverage, the description supplies what the schema cannot: which reference forms are valid, the auth requirement, and the range of operation kinds accepted. With no output schema, it only vaguely characterizes the returned 'détail', which is the remaining gap.

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 0% for the single required 'reference' parameter, so the description carries the full burden — and it does: the reference may be either the operation number from the history or the provider's reference. That tells the agent two distinct accepted formats that the bare 'string' schema does not convey. It still lacks a concrete format example.

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: returns the detail of one account operation, identified by its reference. It also scopes the operation type broadly ('de n'importe quel genre'), which helps separate it from the narrower detail_paiement. It does not name detail_paiement or mes_transactions as alternatives, so the sibling differentiation is only implicit.

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: use it when you already hold a reference and need the full record of that operation. The description adds a real precondition ('connexion demandée la première fois'), which is useful context. However, it never says when to prefer detail_paiement or mes_transactions, nor what to do if the reference is unknown.

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