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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds the access requirement 'Requires FolioFact Pro', which is valuable behavioral context beyond the annotations. It also clarifies the scope of the comparison, but doesn't elaborate on return behavior beyond what the output schema covers.

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 two sentences with no filler. It front-loads the core purpose, lists specific comparison dimensions, and ends with the Pro requirement. Every word earns 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?

Given the tool's moderate complexity, the presence of a rich output schema, and comprehensive annotations, the description is complete. It covers what the tool does, what data it compares, and a key prerequisite. There is no need to explain return values or parameter formats as those are already in structured fields.

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 the baseline is 3. The description adds no parameter-specific details; it only references categories (e.g., valuation, insider activity) that map loosely to the schema but provide no extra semantic meaning.

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: 'Aligned multi-stock comparison' with specific data categories (valuation, financial point, fund conviction, insider activity). The title 'Compare stocks side by side' reinforces the verb and resource, distinguishing it from single-stock tools like get_stock or stock_financials.

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 when to use it through 'multi-stock comparison', which sets it apart from single-stock tools. However, it does not explicitly name alternatives or state when not to use it, so it falls short of a 5.

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