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

Annotations already declare readOnlyHint=false and idempotentHint=false, and the description adds useful context: duplicate calls create two animals, and group creation is gated on is_group=true with group_qty. One inaccuracy: it claims status is required, while the schema makes it optional with a default of 'Active' — a minor misstatement that could mislead.

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?

Two tight sentences with the operation type front-loaded, required-field note, duplicate warning, and endpoint. Nothing extraneous.

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 23-parameter mutation tool with no output schema and low schema coverage, the description leaves the majority of parameters unexplained and gives no guidance on relationships like death_date being tied to certain statuses. It is adequate for the core create action but not for calling the tool correctly with richer payloads.

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?

With 23 parameters and only 30% schema coverage, the description should compensate but only explains type, is_group, group_qty, and status. Most parameters (name, breed, gender, weight, dates, parent ids, market/purchase fields, etc.) receive no meaning from either schema or description.

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 and resource ('add an animal ... to the herd') and distinguishes creation from the update/list siblings. The parenthetical group-creation case and the POST endpoint further pin down what the tool does.

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?

It conveys when to use it implicitly (creating, not modifying, an animal) and warns that duplicate calls create duplicates, but it never names an alternative such as farmbrite_update_animal or farmbrite_list_animals for modification/lookup. The when-to-use context is implied rather than explicit.

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