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

With annotations already indicating a non-read-only, non-destructive operation, the description adds the important requirement of an authenticated Venturu account. It does not disclose other behavioral aspects such as rate limits, success/failure responses, or side effects beyond sending a message, so transparency is only mildly enhanced.

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 concise, with four short sentences that get to the point. The inclusion of the authentication requirement and search tip are useful, though the sentence 'Provide the listing ID and the message to send' is somewhat redundant with the first sentence.

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 two-parameter tool, the description covers purpose, authentication, and how to find a listing ID. However, it does not mention what the tool returns or any side effects beyond sending, and the presence of a sibling tool (contact_broker) without differentiation leaves some contextual 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 coverage is 0%, so the description must compensate. It merely repeats the parameter names ('listing ID and the message') without explaining format, constraints, or semantics beyond what the schema's basic types provide. The description adds little value for understanding the 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 action ('Send a contact message') and target ('a seller on Venturu by their listing ID'), making the purpose obvious. However, it does not differentiate from the sibling tool contact_broker, which likely serves a similar function for brokers.

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 mentions the authentication requirement and suggests using search_businesses to find listing IDs, providing some usage context. However, it does not explicitly state when to use this over contact_broker or any exclusion criteria, leaving the choice ambiguous.

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