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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered; the description adds the useful domain fact that the bin lives in the media library and may be nested. It says nothing about behavior on duplicate names, failure when parentId is invalid, or whether the new bin becomes selected, which would be the value-add 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?

A single front-loaded sentence with the core action first and the optional nesting qualifier second; no filler and nothing redundant.

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 three-parameter mutation with annotations covering safety and no output schema, the description is adequate but thin: it does not indicate what is returned (e.g. the new bin's id), how duplicate names are handled, or what happens if parentId is omitted versus null. These are the gaps an agent would hit on first invocation.

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 description coverage is only 33% (only projectId is documented), but the description partially compensates by explaining that the bin can be created 'inside another bin', which conveys the meaning of parentId. The name parameter is self-evident, though no clarification is given for the null-allowed parentId or the project default beyond the schema note.

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 ('Create a bin') and disambiguates the domain term by glossing bin as 'folder in the media library', plus states the optional nesting capability. It does not, however, distinguish itself from nearby siblings such as create_project, update_bin, or list_folders, so the agent gets purpose but not differentiation.

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?

There is no when-to-use or when-not-to-use guidance, no prerequisites (e.g. must the project be open, must parentId already exist), and no pointer to alternatives like update_bin for renaming an existing bin. Usage is only inferable from the verb.

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