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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the safety story is covered. The description adds the scope of the write (bulk vs single) but says nothing about what happens with an invalid or already-read ID, or what the response contains.

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?

A single short sentence with the scope statement front-loaded and zero padding. It is efficient, though it is minimal enough that a few more words of operational context could have been added without bloat.

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-optional-parameter mutation with full annotation coverage and no output schema, the description is sufficient to call it correctly but thin on outcomes and side effects. The reference to dandori_notifications for obtaining an ID is only present in the schema.

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 id property already documents "ID d'une notification (voir dandori_notifications) ; sans ID, toutes". The description's "toutes, ou une seule" merely restates that default behavior rather than adding new meaning, so 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?

States a specific verb and resource ("Marquer les notifications comme lues") plus the two operating modes (all, or a single one), so the action is unambiguous. It does not name or differentiate against sibling tools such as dandori_notifications, which is only referenced indirectly in the schema.

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 "toutes, ou une seule" phrasing implies the two call modes but gives no explicit when-to-use guidance, prerequisites, or pointer to the sibling tool for discovering notification IDs (that pointer lives in the schema, not the description). Adequate but leaves routing to inference.

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