Numbers: create

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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, but the description adds non-obvious behavior: it refuses to overwrite, needs no app running, and preserves value types exactly (including Arabic text). The overwrite refusal is genuinely useful given the destructive annotation. It does not, however, say what happens on a path collision beyond refusal or whether partial writes can occur.

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 the core action and constraints, and the routing sentence comes last where it belongs. The embedded JSON example consumes a large share of the text and duplicates the schema, which is mild redundancy rather than confusion.

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?

An output schema exists, so return values need not be described. The description covers creation, type fidelity, overwrite refusal, and sibling routing, leaving only edge-case failure behavior unstated. Adequate for a two-parameter create tool.

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 both parameters are already documented in the schema, and the description's inline JSON example largely repeats the schema's own sheets description. Baseline 3 is appropriate since the schema does the heavy lifting and the description adds no syntax or constraint beyond what is already there.

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 ('Create a new .numbers file from data') and immediately scopes it against siblings by naming numbers_import_csv and numbers_add_table as the tools for adjacent tasks. An agent can distinguish this from the other create paths without opening a 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?

Explicitly says when to use it ('when you have the rows') and routes two adjacent cases to alternatives: CSV input to numbers_import_csv, adding a table to an existing file to numbers_add_table. This is the when/when-not/alternatives pattern at full strength.

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