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

With no annotations present, the description carries the full burden of disclosing behavior, but it only states the core action. It does not specify whether the operation is read-only, what the response looks like, how multiple emails are handled, or any rate limits or permissions. The description adds minimal behavioral context beyond the schema.

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 a single, concise sentence with no redundancy or irrelevant details. It is efficiently front-loaded with the core purpose, though it is perhaps too sparse, but for conciseness it earns a high score.

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?

The tool is simple with two parameters and no output schema, but the description provides only the bare action. It does not explain what 'free/busy' means in terms of return value, how to interpret results, or any edge cases. For a tool with no annotations and no output schema, this is insufficient context.

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%, and the description does not elaborate on the parameters 'emails' or 'date'. It fails to clarify the format of emails (e.g., CSV list) or the expected date format, leaving the agent with no additional meaning beyond type strings.

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 'Check free/busy for other people on a date' clearly states the action and resource: checking availability of other people's calendars for a specific date. It uses a specific verb phrase and distinguishes from own-availability tools by saying 'other people,' but it does not explicitly differentiate from similar siblings like check_availability.

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?

No usage guidelines are provided. The description does not mention when to use this tool versus alternatives such as check_availability or search_calendar, nor does it state any prerequisites or context for use. There is no 'when to use' guidance.

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