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

Adds substantial context beyond the annotations: the 2MB storage cap, the 100,000-character inline limit, replacement semantics under the same name at a stable URL, CSV normalization into row objects, and even a summary of the return payload (url, row count, shape, fetch line). The replacement/overwrite behavior is consistent with destructiveHint=true, and the stable-URL nuance usefully qualifies the idempotentHint=false annotation.

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?

Front-loaded with purpose and the key 'never do this' guidance, and nearly every clause carries a distinct constraint. It is a dense single paragraph, however, and the source-selection rules would be more scannable as a short list.

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?

No output schema exists, and the description still covers the return payload, size limits, format conversion, overwrite behavior, and the asynchronous link-mode flow. Nothing material is missing for an agent to select a source and invoke this correctly.

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% and the schema descriptions already carry the mutual-exclusion rule, the CSV `as` modes, the name pattern, and the link-mode flow. The description restates the exactly-one-of rule and the size thresholds but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 (store a JSON or CSV data file) plus the concrete outcome (public URL fetchable by an embed's script), and gives example use cases (product finder, price table, store locator). This clearly separates it from upload_image and from add_content_item in the sibling list.

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 rules out alternatives ('Never paste the data into the embed itself, and never hide it in an image') and gives a decision rule among the three sources: url for anything big, content up to 100,000 characters, mode:"link" for a file only the owner has.

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