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

Annotations indicate readOnlyHint=false (write operation) and destructiveHint=false (not destructive). The description adds behavioral context: the tool fails if the plus-one limit is reached, and requires host role. 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 two sentences with no unnecessary words. It places the core action first, then lists requirements and role. Every part adds value.

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 three-parameter tool with no output schema, the description covers the essential aspects: action, failure condition, required inputs, and user role. It does not mention return value or name match format, but these are minor gaps.

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. It lists the three required parameters by name but provides no additional semantics, formatting, or examples for event_id, parent_guest_id, or plus_one_name.

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 action 'check in', the resource 'one of a guest's allowed plus-ones', and the scope 'at a live event you manage'. It distinguishes from sibling tools like 'check_in_guest' by specifying plus-one-specific behavior.

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 explicitly lists required inputs (event_id, parent_guest_id, plus_one_name) and a precondition (you must be a host). It also states the failure condition (at plus-one limit). However, it does not explicitly name alternatives or when to use this tool over others.

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