add_reading_bookmark

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

The description warns that the tool changes stored DeepTutor learning data and emphasizes user authorization, which adds important behavioral context beyond the annotations' readOnlyHint=false and destructiveHint=false. It does not explain side effects like duplicates or idempotency, but the core mutation risk is clearly disclosed.

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 description is concise and front-loaded with the critical warning before stating the purpose. It could be slightly more streamlined, but there is no filler and the important caution earns its place.

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 an output schema present and all parameters documented in the input schema, the description provides adequate context for calling the tool: purpose, mutation warning, and explicit authorization condition. It does not elaborate on optional parameters like label or source_anchor, but those are already defined 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 description coverage is 100%, so the baseline is 3. The description does not add significant per-parameter meaning beyond what the schema already states, although 'Check the target ID and values' generally reinforces the need to validate material_id, locator, and confirm.

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 clear action and resource: 'Bookmark a unit in a reading material.' It does not explicitly contrast itself with sibling tools like list_reading_bookmarks or delete_reading_bookmark, but the verb and target are specific enough for an agent to identify the operation.

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 gives actionable guidance: call only when the learner explicitly requests the action, and require checking the target ID and values before invoking. It does not mention alternative tools for when not to use it, but it gives clear contextual prerequisites for a write operation.

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