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

Annotations mark it as non-read-only and idempotent. The description adds meaningful context: the webhook fires on new or revised series values, includes payload details (value, verification status, citation), and imposes auth and transport constraints (API key required, https only). This goes beyond the structural annotation hints.

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 sentences front-load the core behavior, then add requirements and management. Every sentence carries distinct information, with no repetition of schema or annotation fields.

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?

The description explains the trigger condition, payload contents, auth requirement, URL scheme constraint, and management operations, all without an output schema. This is sufficient for an agent to understand the tool's role and constraints for a 3-parameter creation endpoint.

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 descriptions cover 100% of parameters with concrete examples ('fred', 'DGS10', https URL). The description adds no new parameter-specific details beyond reiterating https, so the schema is the primary source of parameter semantics.

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 opens with 'Create a monitor' and specifies the exact triggering condition (new period or revised value) and effect (series.updated webhook to your URL). This distinguishes it from fetch tools like get_series/get_observations and management siblings list_monitors/delete_monitor.

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 indicates this tool is for setting up webhooks and refers to management via list_monitors/delete_monitor. It doesn't explicitly contrast with pull-based alternatives, but the event-driven behavior and requirements (API key, https) provide clear usage context. It lands below a 5 because no explicit 'use when...' guidance or exclusions are stated.

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