plunk_create_contact

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

Without annotations, the description carries the full transparency burden. It usefully discloses server-side email normalization, which is a genuine behavioral detail beyond what the schema provides. However, it does not address output/return behavior, error conditions, or the full effect of upserting on existing contact fields.

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 two sentences with no wasted words. The primary action is front-loaded, and the secondary normalization detail is relevant and concisely stated.

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 create/upsert tool with no output schema and no annotations, this description is reasonably clear but incomplete. It explains the upsert-by-email concept and a normalization nuance, yet lacks details on return values, default subscription state, or error handling. It is adequate for a minimal use case but leaves gaps for nontrivial usage.

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 description coverage is low (only 1 of 3 params described). The description adds valuable semantics for the email parameter by explaining normalization, but says nothing about 'data' or 'subscribed'. It partially compensates but leaves two parameters unexplained.

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 action ('Create or upsert a contact by email'), which is specific and distinguishes it from sibling tools like get_contact or delete_contact. It also indicates the identity key (email), making the upsert semantics explicit.

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 phrase 'Create or upsert' implies when to use this tool (for new contacts or updating existing ones by email), but it does not explicitly contrast this with update_contact or mention when not to use it. The context is clear but lacks explicit exclusions or alternatives.

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