Cite from a DOI

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

Adds genuine context beyond the readOnly/openWorld annotations: the external Crossref dependency (which explains openWorldHint) and the fact that the record type determines the citation shape. But it omits practical behavior like what happens when the DOI is not found, rate limits on Crossref, or whether a failed lookup returns an error or a partial citation.

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?

Front-loaded with the core action, then inputs, then the 'all' behavior and an example — every element is scannable. The record-type enumeration is slightly long but earns its place by setting expectations for output shape.

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?

With no output schema, the description carries the return-value burden and does so for the multi-style case (labeled lines above each citation), plus it signals that output shape varies by record type. What a single-style response looks like (bare citation string vs. labeled) is left unstated.

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%, so both parameters are already documented; the description mostly repeats 'doi' and 'style'. It does add the 'all' output behavior (three styles, each labeled above), but its style list ('apa7, mla9, chicago-ad, ieee or all') omits the 'harvard' value the schema declares, a small inconsistency an agent could trip on.

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+resource pair ('Look up a DOI on Crossref and format the citation') and enumerates the record types the lookup can resolve, so an agent knows exactly what comes back. It never names the sibling input-variant tools (cite_from_url, cite_from_isbn), so the differentiation is only implicit in the 'doi' parameter.

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 context for invocation: accepted DOI formats, the valid style values, the special 'all' case, and an explicit example prompt ('Cite 10.1038/nature14539 in APA'). It stops short of exclusions — nothing says to use cite_from_url when the identifier is a publisher URL rather than a DOI, which is the one real ambiguity given the sibling set.

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