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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description reinforces this with 'Read-only (does not book)'. It adds contextual details about the specific doctor and location, plus the behavior of returning all nearest available days when no date is provided. No contradictions with annotations.

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 extremely concise, front-loading the core purpose and then covering optional behavior in one short clause. Every word adds value, and there is no redundancy or unnecessary elaboration.

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 simple read-only availability tool with one optional parameter and no output schema, the description provides sufficient context: the purpose, location, parameter behavior, and read-only guarantee. It does not describe the exact response format, but this is not critical given the tool's simplicity and the lack of an output schema.

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?

The schema covers the single 'date' parameter with a basic format description, but the description adds crucial semantics by explaining what happens when the date is omitted ('all nearest available days'). This goes beyond the schema's minimal 'YYYY-MM-DD (optional)' label and helps the agent understand the parameter's optionality impact.

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 identifies the tool as providing free appointment slots for a specific doctor (vertebrologist) and location (Chernivtsi), and explicitly distinguishes it from booking by stating 'does not book'. This makes the purpose specific and differentiates it from sibling tools like book, cancel, and reschedule.

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 explains the optional date parameter and the behavior when omitted ('all nearest available days'), giving clear context on when to use the tool. The explicit 'Read-only (does not book)' implies that booking actions should be handled by other tools, though it does not name specific alternatives.

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