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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds useful behavioral context beyond those annotations: data is as-filed public data, not live holdings, and includes quarterly-freshness caveats. No contradiction with 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?

Three tight sentences front-load the purpose, enumerate return contents, and add a disclaiming caveat. There is no filler or repetition of schema fields.

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?

With no output schema, the description compensates by listing the main return categories and source caveats. It is sufficient for an agent to invoke the tool correctly, though it does not define 'identifier lineage' or explain behavior when the two funds are not in the same snapshot.

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%, and the schema already documents fund_a, fund_b, and limit, including that limit defaults to 25. The description reinforces that two funds are compared and what overlap means, but it does not add meaningful parameter-level 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?

The description names a specific operation ('Compare two funds'), a specific resource ('same self-hosted SEC Form N-PORT snapshot'), and enumerates concrete outputs: common securities, portfolio percentages, weighted overlap, identifier lineage, and freshness caveats. This clearly distinguishes it from single-fund tools like nport_fund_holdings.

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?

It states the key context: comparisons happen within the same N-PORT snapshot, not across live holdings. It also explicitly disclaims live data and investment advice, which helps an agent avoid misuse. However, it does not name alternative sibling tools or state explicit when-not-to-use conditions.

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