list_calendars

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

With no annotations, the description carries the behavioral disclosure burden. It does indicate a read operation ('Retrieves') and scopes access to the authenticated user, and it describes the output shape. However, it omits important context such as the need for prior authentication via start_google_auth, behavior when the user has no calendars, or any permission/error conditions. This is moderate disclosure for a simple read tool.

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 concise and well-structured with an opening one-line purpose followed by Args and Returns sections. The main sentence is front-loaded and informative. The only minor redundancy is restating 'Required' when the schema already marks the parameter as required.

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 one-parameter read tool, the description is mostly complete: it names the input, the output, and the scope. Yet it lacks any mention of prerequisite authentication, what happens when the email is unauthorized or invalid, or the empty-calendar case. Since there are no annotations to fill these gaps, the description alone leaves some operational uncertainty for an agent deciding how and when to invoke it.

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 0%, so the description must compensate. It does clarify that user_google_email is 'The user's Google email address' and marks it as required. With only one parameter, this is sufficient semantic grounding, though 'Required' mostly repeats the schema's required array.

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 action and resource: 'Retrieves a list of calendars accessible to the authenticated user.' The calendar domain clearly distinguishes it from sibling list tools such as list_spreadsheets and list_gmail_labels. Including the return fields (summary, ID, primary status) further clarifies exactly what the tool produces.

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 when to use this tool: when you need the user's calendars as a list. However, it does not explicitly state when not to use it or name alternatives such as get_events for calendar events or query_freebusy for availability. The agent must infer the right choice from sibling names rather than being guided.

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