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

Adds meaningful context beyond annotations: no bucket keys pass through, the credential performs creation, resulting keys land directly in the vault, and verification is asynchronous ('once the lane finishes'). This complements the destructive/non-idempotent hints with auth requirements and workflow details.

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?

Four tight sentences, front-loaded with the action and mechanism, then security note, then prerequisites, then follow-up. Every sentence carries information, though the density could be trimmed slightly without loss.

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?

With no output schema, the description covers the important gaps: prerequisites, no-key-handling behavior, and how verification is observed asynchronously. Complete enough for a provisioning tool, though return-value specifics remain unaddressed.

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%, so the schema already documents name, bucket, region, and credential_id. The description reinforces the credential's role but adds no syntax or format detail beyond what the schema provides, making the baseline 3 appropriate.

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 and resource ('Create a backup vault') and explains the mechanism: Ankra creates the bucket at the provider using a stored credential. This clearly separates it from list_backup_vaults, get_backup_vault, and verify_backup_vault siblings.

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?

Gives prerequisites ('Requires backups.manage and the organisation's backups feature') and routes the agent to get_backup_vault for verification. It does not state when-not to use it or contrast with adjacent provisioning tools, so it stops short of explicit alternatives guidance.

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