list_assets

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

Annotations already establish the safety profile (readOnlyHint=true, openWorldHint=false), so the description's added value is the returned-field inventory, the documentId/set_field relationship, and the write-path alternatives. It doesn't mention pagination or result limits, which is the remaining gap for a listing tool.

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?

Front-loaded with the core action and scope, then dense but useful detail. The field enumeration is long but earns its place since there is no output schema; no filler sentences.

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 read-only list tool with one fully documented parameter and no output schema, the description usefully substitutes for a return-schema by naming the asset fields. Only pagination/ordering behavior is left unspecified.

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% and the single 'site' parameter is fully documented in the schema, including the list_sites pointer and the empty-tree troubleshooting hint. The description adds nothing about the parameter, so the baseline 3 is correct.

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 a specific verb ('List') and resource ('this site's media library (images and PDFs)'), then enumerates exactly which fields are returned. An agent can distinguish this read/list tool from the write-path siblings without opening any schema.

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 routes the agent away from this tool for writes by naming three alternatives (upload_asset, create_upload_link, import_stock_image), and clarifies the cross-tool relationship with set_field. It doesn't spell out when to prefer this over any other listing, but no close sibling list tool exists, so the guidance is effectively complete.

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