repository_holdings

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

With readOnlyHint and openWorldHint already covering the safety profile, the description still adds meaningful behavior: the first call for a large repository takes 10-20 seconds while SNAC builds the list, results are then cached, and the underlying data source has known coverage gaps. This is exactly the kind of operational and provenance context annotations cannot express.

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 core purpose is front-loaded in one sentence, and the following sentences justify themselves by qualifying result interpretation and latency. The phrasing is slightly discursive (paragraph on survey repositories) but nothing is redundant with the schema or annotations.

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?

There is no output schema, so the description must carry the burden of telling the agent what it gets back; it does this well by characterizing the list's provenance, coverage, and latency. It stops short of describing the record shape or pagination behavior, though pagination is covered by the input schema.

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% and each parameter is already documented, including refresh's 30-day cache semantics. The description only reinforces the title filter ('filtered by title') and the single-repository scope, adding little syntax or semantics beyond the schema. Baseline 3 applies when the schema carries the parameter burden.

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 opening sentence states a precise verb, resource, and scope: it lists the collections SNAC links to a single repository, with an optional title filter. The 'one repository' scoping distinguishes it from the sibling search_collections, which performs cross-repository search. An agent can tell which tool to reach for without opening the schema.

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 description gives strong contextual guidance on when results are trustworthy: the list is SNAC's link table rather than the repository's catalogue, it may miss recent accessions, and 'survey repositories' reflect historical holdings that may have moved. It does not, however, explicitly name an alternative (e.g. search_collections) or state when not to use this tool, so it falls short of full routing guidance.

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