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

Annotations only declare the generic readOnly=false / destructive=false profile. The description adds real behavioral value beyond them: partial-update semantics ('fields not passed are untouched') and the timezone contract (input dates/hours are in the schedule's timezone, not the respondent's, and slots are recalculated on display). It stops short of permissions, limits or error behavior.

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?

Four sentences, no filler, and correctly front-loaded: create-vs-edit contract first, then the two time modes, then the timezone caveat. Every sentence carries a distinct decision-relevant fact.

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 26-parameter, nested-object tool with no output schema, the description covers the highest-value decision points (mode selection, update semantics, timezone) while the schema docs the remaining fields. It is adequate, though it could tie timezone/mode more explicitly to the parameter names it governs.

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 the baseline would be 3, but the description adds cross-parameter meaning the schema does not: what weekly vs slots actually represent and how timezone interacts with how slots are shown to respondents. That semantic layer exceeds the per-parameter descriptions.

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 names a specific verb pair (creates / edits) tied to a specific resource (booking schedule) and explicitly states the scheduler_id switch that selects update over create. This lets an agent distinguish save_scheduler from siblings like delete_scheduler, duplicate_scheduler and get_schedulers without opening 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?

It clearly frames the two operating contexts: omit scheduler_id to create, pass it to edit with untouched fields preserved. It also gives in-tool guidance on when to pick weekly (recurring, 'the most common case') vs slots (one-off dates). It does not, however, name any sibling alternative or exclusion.

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