list_companies

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is already covered. The description adds useful behavioral context not in annotations: results are paged and ordered by filing count. This goes beyond the annotations without contradicting them.

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 short and front-loaded with the core purpose and return behavior. The final 'This tool is read-only' sentence is redundant with the annotations, slightly keeping it from a perfect score, but overall it has no unnecessary bulk.

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 paged list tool with an output schema, rich annotations, and fully documented parameters, the description covers purpose, ordering, paging, and the key alternative. Nothing essential is missing for an agent to invoke this tool correctly.

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 both limit and offset have clear descriptions with defaults. The description adds little parameter-specific detail, but the schema already carries that burden, so the baseline score is appropriate.

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 uses a specific verb and resource: listing companies with ticker, name, and filing counts. It also differentiates from search_filings by explicitly noting that search_filings is for a company's filings, so the agent can distinguish this tool from a close sibling.

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 'Use search_filings for a company's filings,' giving a clear alternative for a different task. It does not enumerate every sibling distinction, but it provides targeted routing guidance for the most likely point of confusion.

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