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

Annotations declare read-only and non-destructive, and the description adds behavioral context: it requires offset and already_shown_urls, and describes automatic routing. 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?

Three sentences, front-loaded with purpose, and each sentence adds value: trigger phrases, routing, and key parameters. No wasted words.

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 no output schema, the description covers routing and essential parameters well. Return format is not specified, but the tool's purpose and pagination behavior are clear.

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 covers 75% of parameters, and the description clarifies usage for offset ('number of contacts already shown') and already_shown_urls (investors only). This adds practical meaning beyond field names.

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?

States it loads more contacts from a previous search result with a specific verb and resource. The routing logic (direct waterfall, company waterfall, investors) distinguishes it from sibling search tools like search_contacts and search_investors.

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?

Explicitly lists trigger phrases ('show more', 'load more', 'more contacts/investors') and explains routing. Does not name alternatives like load_more_companies, but the trigger guidance is clear.

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