Get Contact

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

With no annotations provided, the description carries the burden of behavioral disclosure. It only states 'Get a contact' but omits behavior for missing contacts, duplicate identifiers, or what data is returned. No side effects are mentioned, but basic retrieval behavior is implied.

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 sentence with no wasted words. However, it lacks behavioral details that could be added concisely, such as what happens when both parameters are provided.

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?

Given no output schema and no annotations, the description is adequate for a simple retrieval tool with two optional parameters. However, it could be more complete by stating the uniqueness constraint (either id or email) and return behavior.

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 100%, so the parameters are already described in the schema. The description adds 'by ID or email' but no further context about parameter interaction (e.g., both provided, precedence) or format constraints beyond schema.

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 verb 'Get' and the resource 'contact' from Resend, specifying lookup by ID or email. It distinguishes itself from sibling tools like list-contacts (which return multiple contacts) and create-contact (which creates).

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 implies usage when retrieving a single contact by identifier, but lacks explicit guidance on when to use this tool versus alternatives like list-contacts. No mention of prerequisites or error conditions.

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