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

No annotations are provided, so the description carries the full burden. It states the formula (Carroll) and output unit (kg), but does not disclose any side effects, permissions, or error conditions. For a simple calculation tool, this is adequate but not exceptional.

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 four sentences, each serving a purpose: statement of function, use cases, input/output, and reference to related tools. No extraneous text, front-loaded with the core purpose.

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 presence of an output schema (not shown but indicated), the description does not need to detail return values. It covers purpose, inputs, use cases, and related tools. For a simple calculation tool, this is complete.

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% with descriptions for both parameters. The description adds minimal value by restating the units ('heart girth cm, body length cm') and referencing the Carroll formula, but the schema already provides the necessary details.

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 tool estimates horse weight using the Carroll formula from heart girth and body length. It specifies the verb ('estimate'), the resource ('horse weight'), and the method ('Carroll formula'), distinguishing it from the many other calculation siblings.

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 mentions use cases: 'Use for vets, feed dosing.' and directs to related tools via 'See list_bundles for related animauux calculators.' Lacks explicit exclusions (when not to use) but provides clear context and an alternative.

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