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

The description adds substantial behavioral context beyond the annotations: images are removed from servers, ref_ tokens stop working, the action cannot be undone, tokens not found are reported without failing, the call fails only when nothing was deleted, 50-token limit, ownership by API key, and zero credit cost. These details are not present in the annotations or schema.

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 dense but front-loads the action and key constraints. It could be trimmed slightly (e.g., the credits sentence), but every sentence adds useful operational detail. It is well-structured for an agent to parse.

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 the presence of an output schema, the description does not need to explain return values. It covers all other necessary aspects: scope, irreversible nature, ownership, token limits, error behavior, and the default expiry fallback. Nothing an agent needs to call this tool correctly is missing.

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 parameter description is already detailed, so the baseline is 3. The tool description adds value by clarifying that ref_ tokens are the identifiers returned by create_reference or list_references, and by specifying the 50-token limit, which is not in the schema.

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 gives a specific verb and resource: 'Permanently delete one or more references you created with create_reference'. It clearly distinguishes this tool from siblings such as list_references and create_reference by naming them and describing what deletion entails.

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?

It explicitly states when to call: 'Call it only when the user asks to delete references: it cannot be undone.' It also provides an alternative lifecycle path ('Without this, a reference expires on its own 7 days after its last use or re-upload') and names list_references for discovering tokens, leaving no ambiguity.

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