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

Goes well beyond the annotations: it discloses the 5-minute check cadence, the failure thresholds (2 in a row, or 3 of last 5), the exact incident side effects (inbox message plus one owner email, only after address confirmation), and the recovery notification behavior. This is precisely the operational context an agent needs before creating a watch.

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?

A single front-loaded paragraph where each clause earns its place (limit, cadence, thresholds, notifications, recovery). Dense and slightly run-on, but no filler.

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 4-parameter mutation tool with no output schema, the description covers the behavioral contract well. Minor gaps remain: what happens when the 3-URL cap is exceeded (error vs. replacement) and any failure/error signaling, which matter for an idempotentHint=false write.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: inbox_instance_id is the place you get woken, and the owner email depends on a confirmed address. The 3-URL cap also contextualizes the url parameter. passport_token remains unexplained, keeping it from a 5.

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?

States a specific verb+resource+scope: add an https URL to your uptime-watch, capped at 3 URLs. An agent can immediately distinguish this from uptime_remove and uptime_status without opening any schema.

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?

Usage is implied by the scenario (watch a live app's https endpoint) and bounded by the 'up to 3 URLs' limit, but the description never names an alternative such as uptime_remove for teardown or uptime_status for checking state, nor states prerequisites or exclusions.

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