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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds modest behavioral context by mentioning that both id-keyed and doi-keyed candidates are scanned and that exactly one citation is returned, but it does not disclose behavior when both id and doi are supplied or when no match is found.

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 tight sentence that front-loads the core purpose ('Lookup one citation by id OR doi') and then adds a brief implementation note. There is no filler or redundant information.

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?

For a simple read-only lookup with an output schema present, the description covers the main parameters and the tool's scope. The only notable gap is the lack of explicit guidance on parameter combination and requiredness, but this does not make the tool unusable.

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 0%, so the description must compensate. It does add meaning by identifying id and doi as alternative lookup keys, but it does not specify whether at least one is required, what formats are expected, or what happens if both are provided. This leaves meaningful gaps for a two-parameter tool.

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 states a specific verb ('Lookup'), a precise resource ('one citation'), and the exact lookup keys ('by id OR doi'). It clearly distinguishes this tool from the sibling citations.search tool by emphasizing exact identifier lookup rather than free-form search.

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 clearly implies the tool should be used when the agent has an exact citation id or DOI. It does not explicitly mention alternatives or exclusion conditions, but the lookup/search distinction across sibling tools makes the intended context reasonably clear.

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