find_free_time

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

No annotations exist, so the description carries the full burden, and it does well: it states the max-60-day horizon, the 'today starts from now' edge case, that all-day events don't block by default, and that buffer applies before and after each event. It stops short of confirming this is a pure read with no side effects, and says nothing about the return shape per stretch.

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?

Front-loaded with purpose and output, then a dense but well-ordered per-parameter glossary. Nearly every clause carries a default or format detail; the layout is telegraphic but no sentence is filler.

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 10-parameter tool with no annotations, no output schema, and 0% schema coverage, the description supplies inputs, defaults, edge cases, and an opening statement of what is returned. Remaining gaps are the undocumented 'limit' parameter and the concrete structure of each returned free stretch.

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, and it documents 9 of 10 parameters with formats and defaults ('YYYY-MM-DD', 'HH:MM', ['MO','TU','WE'], buffer semantics, calendars default all). Only 'limit' is left unexplained, which is a minor omission against an otherwise complete parameter glossary.

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?

States a specific verb and resource ('Find open time across your calendars') plus the output shape and ordering ('free stretches each at least duration_minutes long ... earliest first'). This cleanly separates it from siblings like check_conflicts, propose_event, and agenda without the agent needing to open any schema.

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 is implied by the purpose (find availability), and it explains what counts as busy vs free via all_day_blocks and buffer_minutes. However, it never names or contrasts the natural alternatives (check_conflicts, propose_event, agenda), so an agent must infer when this tool beats those.

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