Find available time slots

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

Annotations already carry the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuine behavioral context beyond annotations: it merges busy periods from every checked account and warns that the slot is only trustworthy if every relevant calendar was included — useful for interpreting results and for deciding whether to restrict accounts.

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?

Three sentences, intensely front-loaded, zero filler. Each sentence adds a distinct insight: the merge behavior, the return semantics, and the reporting obligation.

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 read-only, 11-parameter tool with a 100%-covered schema and no output schema, the description covers result interpretation and critical caveats well. It could better address account omission or pagination, but the main operational insight is present.

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%, so every parameter's meaning is documented in the schema; the description adds no parameter-level syntax or format details. Baseline 3 is appropriate when the schema does all the parameter work.

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?

Specific verb+resource: finds free times, and the description clarifies scope ('across all their calendars at once' and 'Merges busy periods from every checked account'). This distinguishes it from check_freebusy, which likely examines a single account/interval.

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 the tool is for finding free/busy windows and hints that accounts matter, but it never names alternatives like check_freebusy or find_cross_account_conflicts, nor states when to prefer it. No when-not-to-use guidance.

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