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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false. The description adds real behavioral value beyond that: it discloses two preconditions and, importantly, that re-enrollment errors if the contact is already enrolled (active or paused), which explains the non-idempotent behavior. Return format is not described, but no output schema exists.

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?

Four short sentences, all load-bearing: core action first, then preconditions, then usage guidance, then error behavior. No redundancy or filler.

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 2-parameter tool with full schema coverage and annotations, the description covers action, preconditions, and the key failure mode. It lacks a pointer to the meisa_list_sequences sibling for finding a slug (though the schema mentions it), which leaves one small gap.

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 100%, so both parameters (email, sequence_slug) are already documented with format and lookup hints. The description restates the identification scheme (email for contact, slug for sequence) but adds no syntax or constraint detail beyond the schema. Baseline 3 applies.

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?

States a specific verb (enroll) and resource (contact in a Meisa automation sequence), and the title reinforces it. An agent can distinguish it from the inverse sibling meisa_unenroll_contact without opening a schema.

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?

Explicitly gives a usage trigger ('when the user wants to start a contact through a drip campaign or automation') and states prerequisites (contact must be 'active', sequence must be 'active'). It does not name the alternative meisa_unenroll_contact or other sequence-start tools explicitly, so it stops short of full routing guidance.

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