plunk_update_contact

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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals key edge cases: email uniqueness returns 409, and the data object has special semantics (null deletes, empty strings ignored, reserved keys filtered). However, it does not mention response formats or error cases like a non-existent contact, leaving some gaps.

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, each providing distinct value: the action, email conflict behavior, and data object rules. No filler or redundancy; information is front-loaded with the purpose first.

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?

The description covers important operational details (HTTP method, conflict behavior, data handling) for an update tool with a nested object and no annotations or output schema. It is not fully exhaustive—missing return value and missing-contact error—but it is complete enough for an agent to select and invoke the tool correctly in most cases.

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 description explains the email parameter ('Pass email to change the address') and the data object semantics, but it leaves 'subscribed' undescribed and relies on id being self-evident. Given the schema description coverage is 0%, this partial compensation is insufficient for full parameter understanding, though it adds meaningful context beyond the 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 action: 'Update fields on an existing contact (PATCH).' This is a specific verb+resource pair, and it distinguishes the tool from siblings like create, delete, and list. The additional mention of email and data behavior further clarifies its scope.

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 an existing contact needs modification, but it does not explicitly compare to alternatives such as subscribe_contact or unsubscribe_contact, which also affect contact fields. There are no clear exclusion criteria or alternative tool references, though the context of 'existing contact' gives implicit guidance.

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