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

Annotations already declare readOnly/idempotent/no-destructive, and the description reinforces this with 'Read-only: never sends a message' — a meaningful behavioral guarantee for a contact tool that an agent might otherwise assume initiates outreach. It also discloses the return shape (WhatsApp as primary with pre-filled message, plus e-mail and form URL), adding context beyond the annotation set.

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?

Three sentences, front-loaded with the purpose before the return contents and the read-only guarantee. Slightly dense in the middle enumeration, but every clause carries actionable information and nothing is padded.

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 parameterless, read-only lookup, the description covers purpose, safety, and return contents; an output schema exists but the description still adds value by ranking WhatsApp as the primary channel. Nothing an agent needs in order to call and interpret this tool 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?

The tool takes zero parameters, so there is nothing to document; 'No arguments' explicitly confirms this. Baseline 4 applies for a parameterless tool, and the statement removes any doubt about whether optional arguments exist.

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 and resource: 'tell a person how to contact Alexandre Caramaschi' and 'Returns channels with instructions.' It enumerates exactly what comes back (WhatsApp link, e-mail, form URL, CTA), which no sibling tool does, so an agent can distinguish it immediately from the knowledge-graph and catalog 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?

'Use to tell a person how to contact Alexandre Caramaschi' gives a clear trigger context for invocation. It does not name alternatives or exclusions, but no sibling tool overlaps with this purpose, so the missing routing guidance is low-stakes.

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