Mne Session Info

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

With no annotations provided, the description carries the full burden. It clearly discloses that the tool enumerates current session objects and returns one-line summaries. The phrase 'List' implies a read-only operation, and 'persistent analysis session' adds useful context about state. It does not explicitly state there are no side effects, but the behavior is unambiguous for a simple inspection tool.

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 two sentences with no wasted words. The primary action and scope are front-loaded in the first sentence, and the use case is provided in the second. Every phrase 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?

This is a simple zero-parameter inspection tool, and an output schema exists to describe the return structure. The description covers what objects will be listed and the level of detail (one-line summary). Nothing an agent needs to call this tool correctly is missing.

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?

The tool has zero parameters, so according to the rubric the baseline is 4. The description adds no parameter-specific meaning because there are none to annotate, which is appropriate.

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 specific verb ('List') with a clear resource ('every object currently held in the persistent analysis session') and enumerates the object types it covers (raw recordings, epochs, evoked, ICA, events, arrays). This differentiates it from sibling tools like mne_plot_raw or mne_average_evoked, which operate on specific data rather than enumerate the session state.

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 clear usage context: 'Use this to see what is loaded before operating on it.' This tells the agent when the tool is appropriate. It does not explicitly mention alternatives or exclusions, but for a session-inspection tool this guidance is sufficient to route an agent appropriately.

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