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

Annotations already cover readOnly, idempotent, non-destructive, and closed-world, so the bar is low. The description adds real value beyond them: it discloses that results are availability-only and never deliver files, that a membership requirement gates actual downloads, and that the false-flag pattern signals a fully absent file set.

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 short sentences, front-loaded with the core purpose, then material scope, then access restriction, then the non-delivery disclaimer. Every sentence earns its place and none repeat the structured fields.

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 needn't be explained, and the description still clarifies what a false result means and the membership constraint on retrieval. For a one-parameter read-only lookup, nothing an agent needs to call it correctly is missing.

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 100% with a single required 'code' parameter that carries its own pattern and example (BTAJ8899). The description adds nothing about the identifier format, so the baseline of 3 applies — the schema does the heavy lifting.

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: checks whether a material has design files and where to obtain them, enumerating the four file types (.skm, .pat, .dxf, texture photos). This is clearly distinct from siblings like check_stock, get_materials, list_filters, and search_materials.

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?

Gives clear usage context: design files exist on sheet materials like tile and flooring, and materials without files return all four as false. It also sets an explicit boundary — 'this tool does not hand out files' — so the agent won't misdirect users toward a download. No explicit routing to a sibling tool, which keeps it at 4.

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