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

Annotations only declare readOnly=false, destructive=false and openWorld=true; the description adds real behavioral context on top: no client is notified, the block is reversible ('removed in Fresha in one step'), no confirmation is required, and a Cotlet API key with app access is needed. It does not cover conflict handling with existing bookings or failure 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?

Purpose is front-loaded and every sentence carries information about scope, parameters, or behavior. It is slightly repetitive, restating 'block time in a team member's calendar' twice at the start.

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 mutating, open-world tool with annotations but no output schema, the description covers purpose, parameter intent, reversibility, notification side effects, and auth. Only edge cases such as overlapping bookings or error responses are left unaddressed.

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%, so all five parameters are already documented. The description's note that title is a reason/blocked-time type and description is a team-visible note largely restates the schema, adding little new meaning.

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 (block) and resource (a time range in one team member's calendar) plus the effect ('no one can book it'). It distinguishes itself from calendar siblings by scoping to a single team member's calendar, though it never names an alternative tool explicitly.

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?

Gives clear usage context ('for a break, training or admin') and a confirmation-policy cue ('runs without asking first'), which tells the agent to proceed without a prompt. It stops short of stating when NOT to use it or which sibling handles multi-member or date-based blocking.

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