Download an object from Scaleway Object Storage

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

Annotations already provide readOnlyHint, idempotentHint, etc. The description adds non-obvious behaviors: truncation to MAX_OUTPUT_CHARS, encoding decision (text vs base64), and the server-wide truncation policy. No contradictions.

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?

Three sentences, front-loaded with the main purpose. Each sentence adds necessary context: purpose, encoding behavior, truncation and alternative. No wasted words.

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 tool's simplicity (3 params, no output schema, safe annotations), the description covers everything needed: what it does, encoding, truncation, and the alternative for large objects. 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?

Schema description coverage is 100%, so the schema already documents all parameters. The description does not add further meaning beyond the schema, e.g., not explaining the region default. Baseline 3 is appropriate when schema is complete.

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 clearly states 'Download a single object's content and metadata', which is a specific verb-object pair. It distinguishes from siblings like scaleway_s3_generate_presigned_url by mentioning truncation and providing an alternative for large objects.

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 tells the agent when to use this tool vs. the alternative: 'for large objects, use scaleway_s3_generate_presigned_url instead'. Also implies this is for small objects due to truncation, and 'single object' clarifies scope.

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