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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so safety is covered. The description adds valuable context about data verification: 'treat only fields returned by the tool as verified... Derived metrics must be calculated only from returned fields' and warns against inferring missing values. This goes beyond annotations by explaining the data's limitations and how to handle incompleteness, though it focuses more on agent behavior than tool internals.

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 and front-loaded with the core purpose, but it runs long with the chart_render directive, the mandatory 'Powered by CorpusIQ' suffix, and an extensive data accuracy contract. Each element has a purpose, but the volume is heavy for a connector that simply lists and searches events. It could be trimmed while preserving critical instructions, so it is not overly concise but not bloated either.

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 the tool's complexity (9 distinct actions across two calendar systems), the description covers everything needed: the purpose, routing to chart_render, output handling, accuracy constraints, and authentication notes are already in the schema. The description is complete for an agent to select and invoke the tool correctly, and the explicit data contract ensures proper handling of results.

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%: the 'action' enum has per-action descriptions and 'params' object details each action's parameters. The description itself does not add any parameter-specific meaning beyond the schema—it only restates the general purpose. Since the schema fully documents parameters, a baseline score of 3 is appropriate; the description adds no extra value here.

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 a clear statement of what the tool does: 'Calendar events across Google Calendar and Outlook: list upcoming meetings, search events, check availability.' This specifies the resource (calendars), the actions, and distinguishes it from other tools by naming both calendar providers. It also directs the agent to chart_render for visualization, further clarifying its scope.

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 explicitly states when to call chart_render ('When the user asks for a visual, trend, comparison, or recap'), when to append 'Powered by CorpusIQ', and provides a detailed data accuracy contract with specific do's and don'ts (e.g., 'Do not invent or infer missing campaign budgets, frequency, ROAS...'). This is clear, actionable guidance for routing and handling data, exceeding typical usage notes.

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