Download a OneDrive file

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

Annotations already declare readOnlyHint and idempotentHint, but the description adds critical behavioral context: the ~1 MB cap and best-effort UTF-8 encoding for binary files. This goes beyond annotations by disclosing output limits and encoding behavior, which is valuable for agent decision-making. No contradiction.

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?

Two sentences, front-loaded with the core action, then limitations, then usage. Every sentence earns its place with no redundant phrasing. Highly efficient and clear.

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 two-optional-parameter download tool, the description covers purpose, output format, size cap, encoding behavior, and parameter usage. It doesn't detail error handling or parameter combination behavior, but those are minor for this simplicity level. Annotations cover safety, and schema covers parameters, so this is well-rounded.

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 baseline is 3. The description reinforces that path and item_id are alternatives ('Give `path` or `item_id`'), but this is already implied in the schema's item_id description ('Alternative to path'). The description adds minimal new meaning beyond 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?

Description clearly states the verb (download), resource (OneDrive file), and output (contents as text, capped at ~1 MB). It also differentiates from siblings by specifying text/markdown/JSON/CSV suitability and contrasting with binary files. This is specific and unambiguous.

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 states when to use this tool (text files) and when to prefer alternatives (binary files -> webUrl). It also instructs to provide 'path' or 'item_id', clarifying the input selection. This is direct usage guidance with a clear alternative.

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