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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds valuable behavioral details: for company type it pulls latest 10-K data from SEC EDGAR/XBRL with correct fiscal year handling, for drug type it pulls FAERS and FDA data, and results are sorted by primary metric. This goes beyond annotations but is not exhaustive.

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 relatively long but each sentence adds meaningful information. It front-loads common query examples. While it could be slightly more concise, it avoids verbosity and is well-structured for quick scanning.

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 only 2 parameters, no output schema, but rich annotations, the description provides sufficient context: it covers both entity types' data sources, sorting behavior, and gives usage examples. For a comparison tool, this is complete enough for an agent to understand when and how to use it.

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 coverage is 100%, so baseline is 3. The description adds context for both parameters: it explains the enum type with 'company' vs 'drug' giving data sources, and for 'values' it clarifies that for company it expects tickers/CIKs and for drug names, along with min/max constraints. This enhances understanding 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 begins with explicit user intents like 'Compare X and Y' and clearly states it performs side-by-side comparison of 2-5 companies or drugs in one call. It distinguishes itself from sequential lookups, making the purpose unmistakable.

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 says 'ALWAYS PREFER over sequential single-pack lookups when comparing entities', providing clear guidance on when to use this tool. It also implies not to use for single entity lookups, and distinguishes between company and drug types with specific data sources.

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