Tag contacts

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

With no annotations provided, the description carries the full burden. It states idempotency and the need for CIVICRM_ALLOW_WRITES=true, which are important traits. It could mention error behavior for non-existent contacts or tags, but overall it covers key behavioral aspects.

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 long, front-loading the purpose in the first sentence and adding key behavioral details in the second. Every sentence is essential and well-structured.

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 simple tool with two parameters, no output schema, and no annotations, the description covers the main aspects: action, idempotency, and prerequisite. It could mention that contacts and tag must exist, but it is sufficiently complete for its complexity.

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 baseline is 3. The description adds no significant meaning beyond the schema; the idempotency note is behavioral rather than parameter-specific. The schema already describes both parameters well.

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 a tag to one or more contacts', specifying the verb and resource. It distinguishes from sibling tools like 'civicrm_untag_contacts' and 'civicrm_add_to_group' by focusing on tagging.

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 mentions idempotency and the required environment variable, which are useful usage hints. However, it lacks explicit guidance on when to use this tool versus alternatives like 'civicrm_add_to_group' or 'civicrm_untag_contacts'.

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