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

The annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description's bar is lower. It still adds meaningful context beyond the annotations: workbook content is never executed, the returned JSON is explicitly untrusted text, and the decoded size is capped at 5 MiB. No contradiction with annotations exists.

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 short sentences, each carrying distinct information: the action and purpose, the return format with a trust warning, and the size limit. The core verb-action is front-loaded; there is no filler or repetition of schema details.

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, read-only tool with 100% schema coverage and safety annotations, the description covers the essential runtime facts: safe inspection without execution, untrusted output, and the size bound. With no output schema present, it even discloses the return format ('original JSON as untrusted text'), leaving little an agent needs before invoking.

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 the schema already documents filename (pattern, length, no path) and content_base64 (canonical padded base64, no whitespace or data URL, byte cap). The description's mention of base64 format and the 5 MiB decoded size reinforces but does not go beyond the schema, warranting the baseline 3.

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 states a specific verb and resource: uploading one base64 XLSX/XLSM to the LifeStep Inspector API to inspect macros, external links, formula counts, and hidden sheets. This concrete scope clearly distinguishes it from the sibling tools (generate_qr, lookup_domain, validate_email), which serve entirely different purposes.

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 intended use case is implied through the enumerated inspection targets (macros, external links, formula counts, hidden sheets), and the 5 MiB limit implicitly excludes larger workbooks. However, there is no explicit when-to-use / when-not-to-use statement or reference to alternative tools, so the agent must infer routing from the description alone.

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