session_undo

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

With no annotations, the description carries the burden. It discloses that the operation reverts a change and that history is limited to 50 entries, which is useful. But it omits what happens when the history is empty, whether redo is cleared, or whether the operation is destructive.

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, efficient sentence that front-loads the verb and object, with a parenthetical adding the relevant limit. Every word 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?

For a no-argument mutation with an output schema, the description is nearly sufficient. It states the core operation and the 50-entry limit. Minor gaps: the relationship to session_redo/session_undo_step and empty-history behavior are implied but not stated.

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?

There are zero parameters, so the baseline is 4. The schema fully documents the empty parameter set (100% coverage), and the description appropriately doesn't add redundant parameter details.

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 clearly states the action ('Revert the most recent state change') and the resource, and adds a history depth limit. However, it does not differentiate from the sibling session_undo_step, which likely performs a similar operation at a different granularity.

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?

No guidance on when to use this tool versus alternatives like session_undo_step or session_redo. It also doesn't mention context such as whether a project must be open or how it interacts with the redo stack.

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