Fund Annual Returns

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds the pagination trait ('paged'), which is genuine behavioral context, but says nothing about return format, ordering, or default page size.

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 clauses, front-loaded with the core operation and then the parameter sourcing. No filler whatsoever.

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?

For a simple read-only, paginated lookup with a fully documented schema and annotations covering safety, this is nearly sufficient. The only gap is that with no output schema, the description could hint at the shape of the per-year return rows, but this is minor.

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 100%, so all four parameters are already documented in the schema, including counter_id's example and source. The description merely echoes the counter_id provenance and optionality of page/size, adding no syntax or format detail 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 ('Get a fund's per-year returns') plus scope (paged), which distinguishes it from the quarterly/annual-adjacent siblings in the fund_* family. It stops short of naming an explicit alternative, so it isn't a 5.

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?

Provides useful sourcing context ('counter_id from fund_hot / fund_list') and marks page/size as optional, but gives no when-to-use-vs-when-not guidance relative to fund_performance or fund_quarterly_returns. Usage is implied rather than stated.

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