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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation/safety profile is covered. The description adds two things beyond that: the plan requirement ('Plan Plus requis'), which is a real access prerequisite, and the effect that progress advances accordingly, tying the call to a side effect on the learning item.

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 compact sentence with the action front-loaded, followed by the effect and the plan gating. Nothing is wasted, though the terseness borders on under-specification for a mutation tool.

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 five-parameter mutation tool with no output schema, the description covers the action, its effect and the plan requirement, but says nothing about validation (e.g. non-idempotent duplicates), streak/other side effects, or what the caller gets back. Adequate but with clear gaps.

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 80%, so the schema already explains date, notes, progress_added, learning_item_id and time_spent_minutes. The description only loosely gestures at progress_added via 'la progression avance d'autant' and adds no format or unit detail, 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?

The description states a concrete verb and resource: 'Noter une séance de lecture ou d'apprentissage' (log a reading/learning session). It is clearly distinct from siblings like dandori_save_learning_item or dandori_add_learning_quote in intent, but it never names an alternative, so the differentiation is only implied.

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?

'Plan Plus requis' gives a gating prerequisite, which is genuinely useful context before calling. However, there is no guidance on when to use this versus dandori_focus_session or dandori_save_learning_item, and no statement about what happens on repeated calls.

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