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

Adds substantial behavior beyond the annotations: the Pro-plan gate returning PLAN_REQUIRED, INVALID_ARGUMENT on ragged/duplicate-column rows, hard limits (10 places, 20,000 rows, 30 columns, 256 KB per MCP request), live re-read semantics, and a meaningful warnings field. With annotations covering the safety profile, this is exactly the extra context the description should carry.

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 purpose followed by plan gate, trigger, two labeled examples, validation rules, and return shape — each block earns its place. It is long, but the length is carried by concrete examples rather than 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?

For a 10-parameter mutation tool with no output schema, it supplies the missing return contract ({id, kind, title, size_bytes, ...}), warning semantics, and the follow-up URL. Nothing an agent needs to call it correctly appears absent.

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 already 90%, so the baseline is 3, but the description goes further with two fully-formed example payloads and the cross-field rule that every row must have one value per column with unique column names — constraints not expressible in the schema itself.

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?

Opens with a specific verb+resource ('Save a chart, a table or a dataset to the user's private workspace'), naming the three artifact kinds it accepts. It also distinguishes itself from the nearest sibling by pointing at workspace_update for later edits.

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 an explicit trigger — 'Use it when the user asks to keep, save or store a chart, table or data' — and routes modifications to workspace_update. It does not explicitly contrast with save_to_collection or state when not to use it, so it falls short of a 5.

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