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

Well beyond the annotations, it discloses that the DPO is alerted, that no external notification occurs, and that a monthly per-plan quota governs agent handling — with the specific fallback that beyond the quota the breach is still recorded with its deadline and only agent involvement stops. That is exactly the kind of side-effect and limit information an agent needs before a mutation.

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?

The main action and the deadline are front-loaded, and most sentences carry real information (DPO alert, no external notice, quota behavior). It is somewhat long and the closing clause about the user's decision versus DPO validation partially restates the earlier DPO alert sentence.

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?

With no output schema, the description does its job by explaining what is returned (the deadline and next steps). It covers side effects, quota limits, and the human decision point, leaving nothing material an agent would need before invoking this mutation.

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 100%, so all five parameters are already documented in the schema, including the discovered_at semantics that drive the 72-hour clock. The description reinforces the deadline concept but adds no syntax or format detail beyond the structured fields, so the baseline of 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 ('Opens a personal data breach'), names the space it is created in, and describes the artifact produced (code plus 72-hour deadline under art. 33(1)). This is clearly distinguishable from siblings like record_request or prepare_analysis, which handle different request types.

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 establishes clear context: opening a breach record starts the 72-hour clock from awareness and explicitly says nothing is notified to the authority or data subjects, which scopes it away from any notification tool. It does not, however, name an alternative sibling or state an explicit when-not condition.

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