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

With no annotations, the description fully discloses key behaviors: the network content for single vs multiple proteins, how numeric values are visualized as halos with color coding, the markdown link instruction, and the suggestion to lower required_score when few interactions appear. This provides a clear behavioral model for the agent.

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 well-structured with bullet points and an example, making it easy to parse. It is longer than strictly necessary but every section serves a purpose: usage scenarios, numeric value semantics, and best practices. The only minor redundancy is repeating the numeric value color logic in two places.

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?

The description covers the main usage contexts, edge cases (large queries, few interactions), and output presentation (markdown hyperlink). With an output schema present, return values are already specified. The only missing piece is explicit handling of invalid protein IDs or error cases, but these are likely covered by the output schema or standard error handling.

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 description adds meaningful context beyond the schema, especially for the proteins parameter with a concrete example and separator notes, and for network_type with the 'physical interactions' trigger. However, species, extend_network, and hide_disconnected_nodes are only covered by the schema's own descriptions, which are already self-explanatory. The description's note on matching parameters to related STRING tools is a useful cross-tool convention.

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 'Retrieves a stable URL to an interactive STRING network for one or more proteins.' The verb 'retrieves' and the specific resource 'interactive STRING network URL' make the purpose explicit. It also distinguishes from siblings like string_visual_network by specifying 'web UI' link generation.

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 provides detailed when-to-use guidance for different query types (single protein vs multiple proteins), when to set network_type, required_score adjustments, and large query handling. However, it does not explicitly name alternative sibling tools or state when not to use this tool, 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.