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

Annotations already declare this is a read-only, idempotent, closed-world, non-destructive computation, so the safety profile is fully covered. The description adds the actual algorithm used, which is genuine transparency about how the result is derived. It stops short of saying whether the result is rounded or how it is formatted.

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 short sentences, front-loaded with the action and method, followed by the usage condition. Nothing redundant or padded.

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?

There is no output schema, and the description never indicates what is returned (a number, a formatted sentence, a table?). For a trivial read-only calculator that is a modest gap, but the combination of an unexplained return value and an unmentioned months parameter leaves the definition only adequate.

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 both parameters are documented in the schema itself; the description adds the useful framing that age is fed into a log formula. However it never mentions the months parameter or how months and years are combined (presumably as a fractional year), so it does not add meaning beyond the schema.

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 (convert a dog's age to human years) and pins down the exact method (UC Davis log formula), which no sibling tool offers. An agent can distinguish it from horse_weight_estimate or pet_cost_calculator immediately.

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?

"Use when someone asks how old their dog is in human years" gives an explicit trigger condition. It names no exclusions or alternatives, but none of the listed siblings is close enough to require disambiguation.

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