download_package

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

Beyond the readOnlyHint annotation, the description discloses time-limited presigned URLs, that the password is shown only here and never logged, and the premature-call 404 behavior. These are significant behavioral traits that annotations do not convey, so the description adds substantial value.

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 front-loads the core action and result in the first sentence, then uses a bullet list for availability contexts and a final paragraph for prerequisites and security notes. Every sentence contributes useful information with no redundancy or filler.

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 output schema exists to document return values, the description covers everything else an agent needs: when to call (after job completion), what to expect (URL and password), time-limited URLs, password security, and the self-hosted vs cloud contexts. No critical information 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?

The single parameter 'id' is already described in the input schema as 'Migration ID' with 100% coverage. The description does not add any further semantic detail beyond repeating that it is for a migration, which is already present. Baseline 3 is appropriate since the schema carries the burden.

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 opens with a specific verb ('Fetch'), a precise resource ('downloadable migration package for a migration'), and the exact result (presigned URL to an AES-256-encrypted zip plus the password). It clearly differentiates from siblings like get_migration or get_migration_jobs by focusing on the package artifact and its delivery mechanism.

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 instructs to check get_migration_jobs first to confirm the GENERATE_PACKAGE job is COMPLETED, and warns that calling too early returns 404. It also provides distinct use-case context for SUPABASE_SELF_HOSTED vs SUPABASE_CLOUD, giving the agent clear guidance on when this tool is appropriate.

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