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

The readOnlyHint annotation already covers the safe-read behavior, so the description is not required to restate that. It adds the return shape ({ pages, events }) and the REST endpoint, which is useful, but it does not disclose pagination behavior or how filtering options affect results beyond what the schema already says.

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 sentences with no filler: the first states the operation and scope, the second gives the return value and API endpoint. Information is front-loaded and every word 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 tool with eight parameters and no output schema, the description is adequate but leaves gaps. It gives the return shape and endpoint, but offers no guidance on when to use filters like include_deleted, only_managed, or last_modified, and only hints at pagination through the 'pages' key.

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 all eight parameters are already documented. The description only adds a high-level connection between the time window and the from/to parameters, providing minimal additional value beyond the schema.

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 clearly states the verb 'Read' and the resource 'events', and adds scope by mentioning the account's calendars and a time window. This distinguishes it from sibling tools like cronofy_delete_event or cronofy_list_calendars, though it does not explicitly name any alternatives.

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 context is implied through phrases like 'across the account's calendars over a time window', which tells an agent this is the tool for reading event data. However, there is no explicit guidance about when to prefer this over related siblings like cronofy_get_free_busy or cronofy_upsert_event.

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