add_note

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

With no annotations provided, the description carries the full behavioral burden. It discloses a genuinely useful operational precondition ('Requires NIGHTSCOUT_READONLY=false') and the timestamping behavior, both of which help an agent decide whether and how to invoke it. It does not disclose success/failure behavior, return value, or side effects, which prevents a higher score.

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?

Three short sentences, each earning its place: the action is front-loaded, the use cases follow, and the prerequisite closes. There is no filler or redundancy, and the critical NIGHTSCOUT_READONLY requirement is included without bloating the text.

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 flat two-parameter write tool with full schema coverage, the description covers the essentials: what it does, when to use it, and a configuration precondition. The notable gaps are the absence of return-value information (no output schema) and explicit routing against the closely related add_treatment sibling, but these are minor given the tool's low complexity.

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 100% — the schema already documents text ('Note text') and created_at ('Timestamp (ISO 8601). Defaults to now.'). The description's 'timestamped' wording only echoes the schema's created_at default rather than adding new semantic meaning, so the baseline 3 applies.

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 states a specific verb and resource ('add a timestamped note to Nightscout') and reinforces it with concrete use cases (meals, activities, symptoms). It implicitly distinguishes itself from the sibling add_treatment by framing this as general context logging, but it never names the alternative explicitly, which keeps it from 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?

The use-case list ('logging meals, activities, symptoms, or any context') provides clear context for when this tool is appropriate, and the broad 'any context' signals general-purpose logging rather than treatment entry. However, it does not say when not to use it or direct the agent to add_treatment for treatment entries, leaving that routing decision to inference.

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