list_files

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

Discloses read-only nature and safe retry, which aligns with annotations. Adds authentication method and max 10 concurrent requests, providing additional context beyond annotations.

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?

Well-structured with distinct sections: purpose, usage guidance, authentication, arguments, return value. Every sentence is informative and necessary.

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 4 parameters and an output schema, the description covers all relevant aspects: parameter details, return structure, authentication, and rate limits. No gaps.

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?

Despite 0% schema coverage, the description thoroughly explains each parameter with ranges, defaults, examples, and cross-references. This fully compensates for the schema's lack of descriptions.

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?

Clearly states 'List images and files stored in the account's File Manager', using a specific verb and resource. Distinguishes from siblings by mentioning get_file, upload_file, and list_file_folders.

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 says when to use: 'discover file_id and hosted URLs for embedding images in campaign or template content'. Also provides explicit alternatives for related tasks.

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