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

No annotations, so the description carries full burden. It states the equation used, which is genuinely useful context, but discloses nothing about units handling, default sex when omitted, output format, or how missing sex affects the result.

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?

A single tight sentence with no waste, front-loaded with verb+resource+method.

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?

A 4-param calculator with no annotations, no output schema, and 50% schema coverage. The description should explain the sex requirement and units more, especially since sex is an enum but not marked required, which creates ambiguity.

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 50%: height and weight are documented in cm/kg, but age and sex have no schema descriptions. The description doesn't clarify sex semantics (required by equation yet not in required list) or age/sex units, leaving a notable gap.

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 (Calculate) and resource (Basal Metabolic Rate) plus the method (Mifflin-St Jeor). It's clear what it does, though it doesn't differentiate from sibling calculate_bmi or calorie_burn.

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?

No guidance on when to use this vs calculate_bmi or calorie_burn, nor any prerequisites. Only implied usage from the name.

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