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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds meaningful context by disclosing the exact result contents and the authentication requirement (free watch key or paid API key), which is not present in annotations. It does not contradict annotations.

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?

Two tight sentences with no filler. The result contents are front-loaded, and the authentication caveat is appended as a compact, necessary qualifier. Every sentence earns its place.

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 simple two-parameter read-only tool with a full input schema and an output schema, the description covers the essential call context: what is returned, recency semantics, and required credentials. Nothing critical for invoking it correctly is missing.

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%, so the input schema already fully documents both parameters. The description adds no parameter-specific detail beyond confirming the tool returns the most recent results, which the schema's 'newest first' description already conveys. Baseline 3 is appropriate.

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 ('retrieve'), a clear resource ('most recent run results for a monitor'), and enumerates the result contents (change details, confidence score, evidence URLs, error information). This clearly distinguishes it from siblings like run_monitor_now or list_monitors.

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 implies the tool is used after a monitor has run and for retrieving result details, but it does not explicitly state when to prefer it over alternatives such as run_monitor_now, list_monitors, or generate_change_report. The authentication requirement is a useful precondition but not usage guidance.

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