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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not explicitly state that this is a read-only operation, what results look like, or whether it modifies any data. The phrase 'check availability' implies read-only but is not explicit.

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, with two short sentences. The purpose is front-loaded and the usage guideline is directly relevant. No unnecessary words are present.

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 tool with no annotations, no output schema, and incomplete parameter coverage, the description is too brief. It does not explain return values, how to interpret availability results, or how duration affects the check. The presence of similar tools like check_freebusy further highlights the lack of distinguishing details.

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 for parameter meaning. It mentions 'date' as the target date but does not explain the 'duration' parameter or provide format expectations. This is insufficient for two parameters.

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 states the tool's function with a specific verb ('Check'), resource ('your calendar availability'), and scope ('for a date'). The added instruction 'ALWAYS call before creating events' reinforces its purpose and distinguishes it as a prerequisite step for event creation tools.

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 instruction to 'ALWAYS call before creating events' provides explicit context for when to use this tool. However, it does not mention alternatives or any exclusions, so it lacks a full 'when-not-to-use' clause.

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