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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds real domain behavior beyond that: commission is netted out, inflation is subtracted to get real yield, and unbonding days earn no rewards during the lockup comparison — details an agent cannot get from the annotations.

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 first sentence is dense and front-loaded with the actual capability set. The following four sentences are largely meta-instructions about argument nesting and schema compliance, and they overlap ('Put tool fields inside inputs' vs 'Do not pass the REST calculator field inside MCP arguments'), so some text does not 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 no explanation, and annotations cover the safety profile. However, with nine undocumented nested parameters plus an enum for rate_type and a oneOf for periods_per_year, the description leaves an agent guessing on units and defaults (percent vs fraction, continuous compounding), which is a real gap for a numeric calculator.

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 carries the burden for nine nested fields. It maps conceptually to most of them (compounding/periods, commission_pct, inflation_pct, lock_days, unbond_days, alternative_apy_pct, rate_type via APR<->APY), but never explains rate_pct or principal, and the statement about supplying 'units or modelVersion' references a units field that does not exist.

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 names a specific computation domain (staking yield math) and enumerates the exact operations: APR<->APY with compounding, commission netting, inflation-adjusted real yield, lockup valuation, and opportunity cost versus an alternative APY. An agent can immediately tell this apart from the other buscalc_* calculators, which cover unrelated domains.

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?

Usage is implied by the enumerated computation types (e.g. use it when you need real yield after inflation or opportunity cost vs an alternative APY), but no explicit when-to-use/when-not-to-use statement or sibling alternative is named. The remaining sentences give argument-placement instructions rather than selection guidance.

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