nexo_heartbeat

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

Describes key behaviors: updates session task, checks inbox/pending questions, auto-detects trust events, and outputs a NOW_UTC line. Without annotations, this covers essential behavioral traits, though it doesn't explicitly state it's non-destructive (likely safe given the context).

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 with a brief purpose, a call-to-action, output details, and parameter list. It is slightly verbose but every sentence adds value. Could be more concise, but still effective.

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 no output schema, the description explains the output (NOW_UTC line) and how to use it. It covers all necessary aspects: purpose, usage, parameters, and output. Complete for a heartbeat tool.

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?

Input schema has 0% description coverage, but the description thoroughly explains each parameter: sid from nexo_startup, task as brief work description, context_hint for sentiment detection and RAG. This fully compensates for the lack of schema descriptions.

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 function: 'Update session task, check inbox and pending questions. Auto-detects trust events.' It uses specific verbs and resources, and distinguishes itself from sibling tools by being a heartbeat call at the start of interactions.

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 instructs 'Call this at the START of every user interaction (before doing work).' This provides clear when-to-use guidance and implies no other usage context.

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