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

Annotations already declare readOnlyHint=false and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond that: the encoding rule (base64 for binary, plain text otherwise), the 5 MB limit, and the replacement semantics ('same label replaces earlier version'). This gives the agent a fuller picture of side effects and constraints, exceeding what annotations alone provide.

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?

The description is a single paragraph, but every sentence earns its place: purpose, encoding guidance, size limit, replacement semantics, and an optionality note. The core function is front-loaded, and there is no fluff. It is concise yet informative without being verbose.

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?

Given 5 parameters and no output schema, the description covers the essential usage decisions: what to store, how to encode, size limits, overwrite behavior, and whether the tool is needed at all. It doesn't mention error handling or return values, but that is not critical for a store operation without a defined output. An agent can call this tool correctly with the guidance provided.

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 covers all parameters (100% coverage), so the baseline is 3. The description adds practical meaning: it clarifies when to use base64 encoding (for binary content) versus utf8, reinforces that label is the identity and that storing the same label overwrites, and hints at the size constraint. This goes beyond the raw schema descriptions and helps an agent correctly populate fields.

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 tool stores a file the user made, with concrete examples ('pitch deck, brief, prompt library, service terms') and explains it appears in the business Cupboard. The verb+resource is specific and distinguishes it from sibling tools like business_list or business_draft, which have 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?

It provides clear guidance on when to use (to store files you made) and when not (files larger than 5 MB: 'put anything larger somewhere else and add a link block to the storefront'). It also signals optionality ('many businesses never produce a file and that is fine'), which helps an agent decide whether to skip the tool. It doesn't name a specific alternative tool, but the advice is actionable enough.

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