session_info

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

There are no annotations, so the description carries the full burden of behavioral disclosure. 'Get information' suggests a read-only operation, but it does not explicitly state side effects, permissions, or what 'session' scope means. For a zero-parameter query tool this is acceptable but minimal.

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 a single, front-loaded declarative sentence with no redundant words. It earns its place and leaves no room for unnecessary detail.

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 simple zero-parameter getter, this is nearly sufficient, but 'information' is vague and there is no output schema. An agent can invoke the tool correctly but may not know what fields or shape the returned session information will take.

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 and the schema is trivially fully covered with an empty object, so the baseline is 4. There is no parameter information for the description to add, and none is missing.

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?

Description states a specific verb ('Get') and resource ('information about the current Claude Code session'), making the core function clear. It does not explicitly differentiate from sibling context-test_contextInfo, which may also return session-related data, so it stops short of a 5.

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 is provided on when to use this tool instead of sibling session/context tools, and no exclusions or prerequisites are mentioned. The only usage signal is the generic implication that you should call it when you want session information.

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