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

Annotations already indicate idempotency (idempotentHint: true) and non-read-only (readOnlyHint: false). The description adds valuable context beyond that: it specifies the dedicated 'CRM Imports list' where the contact is saved and explains the return behavior (existing contact). This enriches the agent's understanding of side effects and storage location.

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 three sentences with zero redundancy. It front-loads the primary purpose, then gives usage context and workflow in a logical order. Every sentence earns its place.

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 output schema and simple behavior, the description covers all needed aspects: what it does, when to use it, where data goes, and what to do next. The mention of 'return the existing contact' implies the return behavior sufficiently. No critical information is missing.

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% and every parameter has a description. The tool description adds no additional parameter-specific semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 states a specific verb ('Create'), resource ('contact'), and source ('known LinkedIn profile URL'), and explicitly distinguishes the idempotent behavior ('or return the existing contact'). It also differentiates from search tools by noting 'do not need to run a search', making its purpose unmistakable.

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 gives explicit usage conditions: 'when you already know the exact profile URL and do not need to run a search', which implicitly tells agents when not to use it (i.e., when searching is needed). It also mentions the downstream workflow (pass to add_contacts_to_campaign), providing clear routing guidance among siblings.

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