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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: data is 'live', sourced from 'StakeWiz API', and includes commission rates. This goes beyond the structured annotations by explaining the data's origin and composition.

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 sentences with no fluff. The main action and formula are front-loaded, and the data source is stated in the second sentence. Every word contributes to understanding the tool's behavior.

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 tool has no parameters and no output schema, the description fully covers what the agent needs: what it returns (APY breakdown), how it's computed, and where it comes from. For a simple read-only informational 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?

There are zero parameters, so the baseline is 4. The description doesn't need to explain parameters since the input schema is empty, and it doesn't attempt to invent any.

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's purpose: 'Get live APY breakdown' and specifies the components (base staking APY + Jito MEV APY = total APY). This distinguishes it from siblings like get_staking_summary and get_staking_policy, which address different concerns.

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 description implies usage context by mentioning 'live APY breakdown' and 'Data from StakeWiz API', which tells the agent when this is relevant (fetching APY data). It does not explicitly contrast with alternatives, but the specificity of the purpose provides sufficient contextual guidance for a read-only informational tool.

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