NEXO Brain

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

With no annotations provided, the description carries full burden. It discloses the immediate effect ('Removes it from active sessions immediately') which is valuable behavioral context. However, it doesn't mention potential side effects, error conditions, or what happens to session data after closure, leaving some behavioral aspects unclear.

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?

Perfectly front-loaded with the core purpose in the first sentence, followed by usage guidance and parameter explanation. Every sentence earns its place with zero wasted words, and the Args section is appropriately brief for a single parameter.

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?

Given the tool's simple destructive operation (session closure), no annotations, and the presence of an output schema (which handles return values), the description is nearly complete. It covers purpose, usage, parameter meaning, and immediate effect. The main gap is lack of detail about what 'cleanly close' entails operationally.

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?

With 0% schema description coverage and only 1 parameter, the description adds essential meaning by explaining that 'sid' represents the 'Session ID to close.' This compensates fully for the lack of schema documentation, though it doesn't provide format examples or validation rules.

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 specific action ('cleanly close a session') and resource ('session'), distinguishing it from sibling tools like nexo_session_diary_read/write which interact with session diaries rather than managing session lifecycle. It provides a concrete verb+resource combination that is unambiguous.

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?

Explicitly states when to use this tool ('Call this when ending a conversation to avoid ghost sessions'), providing clear context for invocation. It differentiates from other session-related tools by focusing on termination rather than diary operations or status checks.

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