sendgrid_add_contact

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

With no annotations provided, the description needs to disclose behavioral traits. It only says 'Add or update,' but does not explain that it is an upsert operation, what happens to existing fields, potential side effects (e.g., list membership changes), or any mutation details. The minimal description leaves the agent uninformed about important behavior.

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, direct sentence with no extraneous words. It is efficient, but could be slightly improved by clarifying the upsert nature without adding length.

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 the tool has 6 parameters (2 required, 4 optional) and no output schema, the description is insufficiently complete. It does not explain the upsert semantics, the optional parameters (like list_ids, phone_number), or what the tool returns. More context is needed for an agent to use it effectively.

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%, with each parameter described in the input schema. The description adds no extra meaning beyond what is already in the schema. Therefore, it merely meets the baseline expectation.

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 tool's purpose: 'Add or update a marketing contact in SendGrid.' It uses specific verbs ('add or update') and identifies the resource ('marketing contact'), distinguishing it from sibling tools like sendgrid_list_contacts (for listing) and sendgrid_send_email (for sending).

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 provides no guidance on when to use this tool versus alternatives. It does not mention that it performs an upsert (create or update), nor does it suggest when to use sendgrid_list_contacts for reading contacts or sendgrid_send_email for sending. No context about prerequisites or exclusions is given.

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