sendgrid_add_contact

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

The description only states that it adds or updates, implying a write operation. With no annotations, the agent gains no understanding of idempotency, duplicate handling, rate limits, or required permissions. Critical behavioral details are missing.

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 of 8 words, which is appropriately concise. It conveys the core purpose without extraneous detail, though a slightly more informative phrasing could improve completeness without sacrificing conciseness.

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's simplicity and full schema coverage, the description is minimally sufficient but lacks context such as how duplicate emails are handled, whether the operation is upsert, and what the expected response looks like. No output schema is provided, so more description would help.

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?

Input schema has 100% parameter coverage, so the schema already documents each parameter (api_key, email, etc.). The description adds no extra parameter-level context beyond what the schema provides, resulting in a baseline score of 3.

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 ('Add or update') and the resource ('marketing contact in SendGrid'). It effectively distinguishes from sibling tools like 'sendgrid_list_contacts' (which only lists) and 'sendgrid_send_email' (which sends emails).

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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of prerequisites (e.g., having an existing list), scenarios where update occurs instead of add, or when to choose a different SendGrid tool.

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