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

With no annotations, the description carries the full behavioral burden. It discloses the critical value-parsing behavior: numbers/dates parse and leading = becomes a formula, plus the RAW option to avoid that. It also specifies the append location. This is substantial transparency for a mutation tool.

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 with the purpose front-loaded and the key behavioral nuance second. No filler; every clause adds value, and the structure is easy to scan.

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 five-parameter append operation with no output schema, the description covers the core behavior, value handling, and gives a range example. It does not mention error cases or alternative tools, but the essentials for correct invocation are present. Slightly more would be ideal but not required.

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 60%, and valueInput lacks a description in the schema. The description explains the enum values and their effect, adding meaning beyond the schema. It also clarifies the interpretation of the values parameter, partially compensating for the incomplete 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?

The description clearly states the action: 'Add rows after the last row that holds data' and frames it as 'the usual way to add records to a tracker.' This distinguishes it from update/clear operations and from the Excel sibling. The specific resource and behavior are 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?

It implies the primary use case (adding records) and hints at the distinction from overwriting, but does not explicitly mention alternatives like update_google_sheet_range or clear_google_sheet_range. The context given is enough for an agent to infer when to use it, though not exhaustive.

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