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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint false, so the safety profile is covered and the description only needs to add context. It does add a little ('Returns due date and gestation milestones'), though that is partly redundant with the output schema, and it discloses no calculation assumptions or validation rules.

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, front-loaded with the purpose and inputs, with no filler. The list_bundles tail is the only sentence that does not clearly earn its place.

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?

An output schema exists, so return values need not be explained, and the description is adequate for a two-parameter read-only calculator. But the wrong enum list plus the wrong parameter name leave the agent without a reliable picture of valid inputs, which is the one thing that matters most here.

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 0%, so the description must carry the parameter burden, and instead of clarifying it misinforms: it names 'species' (the parameter is 'animal') and lists dog/cat/horse/rabbit/cow, which contradicts the actual enum (dog/cat/rabbit/hamster). An agent following the description could pass an invalid value such as 'horse'.

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 concrete verb+resource ('Compute due date for animal breeding') and names the two required inputs, so the tool's function is unambiguous. However, it does nothing to separate itself from close siblings like calculate_dog_pregnancy, calculate_cat_pregnancy, calculate_pregnancy_due_date and calculate_due_date.

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 only guidance is the thin audience note 'Use for breeders' plus an unrelated pointer to list_bundles. Nothing tells the agent when to prefer this generic tool over the species-specific pregnancy calculators in the sibling list, which is the main selection risk here.

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