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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value by enumerating the exact fields returned (authors, journal title, ISSN, year/month, subjects, keywords, abstract, DOI, full-text URL), which tells the agent what to expect beyond the annotations. It doesn't discuss rate limits or error cases, but for a read-only detail endpoint this is adequate.

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?

Two sentences, both information-dense. The first states the action and the return payload; the second gives usage sequencing. No filler or repetition of schema details.

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 single-parameter read-only detail tool with a rich output schema, the description is nearly complete. It names the input source (search results), the output fields, and the workflow position. It doesn't mention pagination or error handling, but those are unlikely to matter for a detail-by-ID endpoint, and the output schema covers return structure.

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% and the schema already describes article_id as a 32-character hex string with an example and provenance ('Obtain from article_search results'). The description reinforces the parameter's role by saying 'by its DOAJ article ID' and 'for a specific article,' adding a little context about what the ID identifies. Since the schema carries most of the weight, a 4 is appropriate rather than 5.

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 uses a specific verb ('Retrieve full metadata') and resource ('single open access article from the Directory of Open Access Journals by its DOAJ article ID'). It clearly distinguishes from siblings like doaj.articles.search and doaj.journals.detail by specifying it operates on articles by ID and returns the complete bibliographic record.

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 explicitly states 'Use after doaj.articles.search to get complete details for a specific article,' which provides clear sequencing guidance and implies the alternative (search) to use first. This is direct when-to-use guidance.

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