create_contact_tag

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

Annotations indicate readOnlyHint=false (write operation) and destructiveHint=false (non-destructive). The description adds that it is 'Reversible' and provides examples of the association types, which provides behavioral context beyond the annotations. No contradiction with annotations.

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 well-structured with a header line (emoji, HTTP method, endpoint), a clear purpose statement, and context. It is front-loaded with essential info. Minor redundancy at the end ('Create a contact tag object') but still concise overall.

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 simplicity of the tool and no output schema, the description is sufficiently complete. It explains the action, notes reversibility, and provides examples. It could mention prerequisites (existing tag and contact IDs) but the schema handles that.

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 input schema already documents the parameters 'tag' and 'contact' with descriptions. The description does not add extra semantic meaning beyond what the schema provides, meeting the baseline for high coverage.

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 verb 'Add a tag to contact' and specifies the resource as an association between a contact and a tag. It provides examples like 'tags a contact, adds a contact to a list/automation,' which differentiates it from sibling tools like 'create_a_new_tag' (creates a tag) and 'remove_a_contacts_tag' (removes an association).

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 includes the HTTP method and endpoint, and notes that the action is reversible. It gives examples of when to use it (tagging a contact, adding to a list/automation), but does not explicitly state alternatives or when not to use it. The context is clear enough for an agent to decide.

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