Add sheet

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

Annotations already establish that this is a non-readonly, non-destructive, non-idempotent mutation, so the description does not need to repeat that. It adds genuinely useful context—failure on uploaded workbooks and the active-sheet side effect on unqualified references. It stops short of describing permission requirements, persistence/undo behavior, or failure modes like duplicate sheet names, which leaves the mutation profile only partially covered.

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 tight sentences: core action first, applicability second, sibling routing and return value last. No repetition of the title and no filler; every clause carries distinct information.

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-parameter mutation with full schema coverage and no output schema, the description covers action, scope, constraints, alternatives, and the return payload. Minor gaps remain around naming collisions and post-call state visibility, but nothing an agent needs to invoke it correctly 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?

Schema coverage is 100%, with both name and session_id documented in the schema, so the baseline is 3. The description adds implicit meaning about where the sheet lands (end of the workbook) and the active-sheet effect, but says nothing extra about naming constraints or how session_id relates to list_sessions.

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 and resource ("Add an empty sheet") and adds the key behavioral detail that it is appended at the end and made active. It explicitly names sibling alternatives (rename_sheet, delete_sheet, set_inputs), so an agent can distinguish it from adjacent tools without opening any schema.

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 gives a clear positive condition (blank, created-blank sessions) and an explicit exclusion (uploaded workbooks, where it fails) plus a named alternative workflow (use set_inputs on existing sheets). It does not cover ordering or prerequisite steps like session creation beyond the parenthetical, but the when/when-not split is unusually clear.

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