NEXO Brain

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

No annotations are provided, so the description carries the full burden. It describes the tool's behavior as updating a session task and checking inbox/pending questions, which implies it's a read-and-update operation. However, it lacks details on permissions, side effects (e.g., whether it modifies data beyond the session task), rate limits, or error handling. The description adds some context but misses key behavioral traits for a tool with no annotation support.

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 well-structured and concise. It starts with the core purpose, followed by a critical usage guideline, and then parameter explanations. Each sentence earns its place: the first defines the tool, the second provides timing, and the third clarifies parameters. There is no wasted text, and information is front-loaded effectively.

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 has 2 parameters, no annotations, and an output schema (which handles return values), the description is reasonably complete. It covers purpose, usage timing, and parameter semantics. However, as a session management tool with potential side effects, it could benefit from more behavioral context (e.g., idempotency, error cases) to fully guide an agent, especially without annotations.

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 0%, so the schema provides no parameter documentation. The description compensates by explaining both parameters: 'sid: Your session ID from nexo_startup.' and 'task: Brief description of current work (5-10 words).' This adds essential meaning beyond the bare schema, clarifying the source of 'sid' and the format for 'task'. However, it doesn't detail validation rules or examples.

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 tool's purpose: 'Update session task, check inbox and pending questions.' It specifies the verb ('Update', 'check') and resources ('session task', 'inbox', 'pending questions'), making the action concrete. However, it doesn't explicitly differentiate this from sibling tools like 'nexo_status' or 'nexo_startup', which might have overlapping session-related functions.

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 provides explicit usage guidance: 'Call this at the START of every user interaction (before doing work).' This clearly indicates when to use the tool (at interaction start) and implies when not to use it (during or after work). It doesn't name alternatives, but the timing directive is sufficiently precise for an agent to apply it correctly.

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