NEXO Brain

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

No annotations are provided, so the description carries full burden. It states this is a 'write' operation, implying mutation, but doesn't disclose behavioral traits like permissions needed, whether it's idempotent, what happens on failure, or how it interacts with session state. The description adds minimal context beyond the basic action.

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, efficient sentence that front-loads the core purpose with zero wasted words. Every part earns its place by specifying the action and key content areas.

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 10 parameters with 0% schema coverage and no annotations, the description is incomplete—it doesn't explain most parameters or behavioral aspects. However, the presence of an output schema reduces the need to describe return values. For a write tool with many undocumented parameters, this is minimally adequate but has clear gaps.

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 parameters are undocumented in the schema. The description mentions 'decisions, discards, and context for next session' which partially maps to some parameters (e.g., 'decisions', 'discarded', 'context_next'), but doesn't explain the other 7 parameters (like 'mental_state', 'user_signals', 'domain') or provide format/usage details. It adds some meaning but doesn't compensate adequately for the coverage gap.

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 ('Write end-of-session diary') and the content scope ('with decisions, discards, and context for next session'), providing a specific verb and resource. However, it doesn't explicitly differentiate from its sibling 'nexo_session_diary_read', though the 'write' vs 'read' distinction is implied.

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 no guidance on when to use this tool versus alternatives, prerequisites, or exclusions. It mentions 'end-of-session' context but doesn't specify what constitutes a session or how this relates to other tools like 'nexo_decision_log' or 'nexo_change_commit'.

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