find_free_slots

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

Annotations already declare readOnlyHint and destructiveHint, and the description reinforces this ('Read-only: it never books anything') while adding new context: it requires a Microsoft account, and it handles time zone, weekends, working hours, minimum notice, and gaps automatically. This goes beyond what annotations convey, providing critical operational details.

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: it starts with the core purpose, then the output shape, then usage guidance, then prerequisites, and finally a clear read-only note. Every sentence adds value, with no filler. The 'nota' field is mentioned but not defined, which is a minor omission, but overall the structure is excellent.

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 covers the output format, the pre-handled logic (time zone, weekends, etc.), the Microsoft account requirement, and the read-only nature. It lacks a definition of 'nota' and does not explicitly state that parameters like work_start/work_end override the defaults, but these are minor gaps given the schema's thorough parameter descriptions. Overall, the description is comprehensive enough for an agent to use correctly.

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%, and the schema already documents all 7 parameters with descriptions. The tool description does not add any parameter-specific semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 tool computes free meeting slots from the calendar, with a specific output structure. It explicitly contrasts with list_events ('use this instead of deriving availability from list_events'), making it easy for an agent to distinguish this tool from its siblings.

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 provides direct usage guidance: it recommends using this tool over list_events for availability, and mentions that booking requires create_event which needs human approval. This explicit when-to-use and when-not-to-use guidance is exemplary.

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