Fetch

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

No annotations are provided, so the description carries the full behavioral burden. It implies a read operation via 'Retrieve' but does not state read-only safety, error behavior for unknown IDs, rate limits, or what 'complete material information' actually includes.

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?

A single front-loaded sentence with no filler, which is appropriate for a one-parameter tool. It is efficient, though it spends its words on inputs rather than on routing or behavior.

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 need not be explained. However, for a tool sitting among three similarly named siblings, the description omits the differentiation and usage conditions an agent needs to invoke the right one.

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 0% and the single parameter is an opaque 'idx' string, so the description must compensate. It usefully clarifies that the value can be a Materials Project ID, a formula, or a chemical system, but it does not state the expected string format for any of those forms.

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 names a clear verb (Retrieve) and resource (complete material information), and it specifies the accepted key types (Materials Project ID, formula, chemical system). It does not, however, differentiate itself from siblings like fetch_many, fetch_all, or search, so an agent cannot tell from the text alone why it should pick 'fetch' over those.

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?

There is no explicit when-to-use guidance or exclusion criteria. Given the sibling set (fetch_many, fetch_all, search), the agent is left to infer that 'fetch' is the single-item lookup, but the description never states this or names any alternative.

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