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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds meaningful context beyond those hints by disclosing that some information is withheld and why, including disclosure rules and a not-advice notice, which an agent would not otherwise know.

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 description is a single dense, well-structured sentence with a front-loaded core statement followed by a clear colon-delimited list of content topics. Every element adds information without wasted words or repetition.

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 zero parameters, rich annotations, and no output schema, the description adequately specifies the tool's scope, content, citation URLs, and a practical trigger condition for use. A minor gap is that it does not describe the exact return format, but this is not critical for a read-only methodology document tool.

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?

The tool has zero parameters and schema description coverage is 100%, so there are no parameters that need explanation. The description still orients the agent toward what the methodology content covers, which is appropriate for a no-parameter reference lookup.

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 identifies the tool as the source for how fund figures are measured and what is withheld, enumerating specific content areas such as index construction, since-inception returns, and disclosure rules. This strongly differentiates it from siblings like get_fund and get_fund_history, which provide fund data rather than methodology.

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 explicitly tells the agent when to consult this tool: 'Read this once before quoting any fund number to a client.' This gives a clear use condition, though it does not explicitly name sibling alternatives or state when not to use the tool.

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