post_contact

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

With no annotations, the description carries the full burden. It lists error codes ('noent', 'exists', 'no_match'), which partially discloses failure modes. However, it omits behavioral traits like idempotency, side effects, or authentication requirements. The error codes are useful but insufficient for full transparency.

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 very short (two lines) and front-loaded. It avoids unnecessary words but could be slightly more structured (e.g., bullet points for error codes). Overall, it is concise with no waste.

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 complexity (12 parameters, nested arrays for addresses/emails/etc.) and the presence of an output schema, the description is incomplete. It does not explain the tool's capabilities (e.g., creating a full contact with sub-resources in one call) or provide guidance on the data structure. Error codes help but are insufficient for this rich schema.

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 schema already documents all parameters. The description adds no extra meaning beyond the schema. It does not clarify relationships or important parameters (e.g., notes description is misleadingly identical to last_update in schema, but description doesn't address this). Baseline 3 is appropriate.

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 'Creates a new ContactEntry', which is a specific verb+resource. It implicitly distinguishes from sibling tools like 'put_contact_id' (update) and 'post_address_number_address_url_email' (sub-resource creation). However, it does not explicitly differentiate itself from other post tools.

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 usage guidelines are provided. The description does not indicate when to use this tool versus alternatives (e.g., updating a contact via 'put_contact_id', creating sub-items via dedicated post tools). No context about prerequisites or exclusions.

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