read_spreadsheet

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

Annotations already declare readOnlyHint/idempotentHint/openWorldHint and destructiveHint=false, so safety is covered; the description adds genuinely useful behavior beyond that — the discovery-then-read workflow, format defaults, and that headerRow only affects json output. It does not disclose how the url/data/path inputs interact (precedence, mutual exclusivity) or what errors occur on unreadable files.

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?

Four tight sentences, front-loaded with purpose, then the operational pattern, then the optional knobs. No restatement of the title and no filler; every clause carries a decision an agent needs.

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 9-parameter tool with no output schema, the reading workflow and output-format behavior are reasonably covered. The critical gap is the unexplained url/data/path trio — an agent cannot determine whether these are alternatives or combined inputs, which is a real risk of a failed call.

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?

With only 56% schema coverage, the description does add meaning for `sheet` (omit to list sheets), `range` (A1-style) and `headerRow` (json keys). However, the three input-source parameters (url, data, path) and `mimeType` are undocumented in both schema and description, leaving an agent unable to tell which source to supply.

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 (read) plus the concrete resource set (.xlsx/.xlsm/.xls/CSV), which effectively distinguishes it from the sibling readers read_pdf, read_docx and read_text_file by file type. It does not name those siblings explicitly, so the differentiation is implicit rather than stated.

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?

The two-step pattern is spelled out precisely: call without `sheet` first to discover sheet names, then call again with `sheet` to fetch data. That is clear when-to-use guidance for the main decision point, but there is no guidance on choosing between this tool and its sibling file readers, and no exclusions.

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