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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the '[read]' prefix adds little. What the description does add beyond structured data is the return value shape: a `seliee_article_language` value such as `english`, which matters since there is no output schema. It stops short of saying what happens if the article has no language set or the id does not resolve.

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 compact sentences, front-loaded with the resource and the return type, then the argument instruction. Nothing redundant beyond the '[read]' tag, which is minor.

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 trivial single-value lookup with annotations covering the safety profile and the description covering the return type, this is nearly complete. The remaining gap is the identifier-precedence / at-least-one-required question, which the schema's all-optional fields leave ambiguous.

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 carry the load. It clarifies that the two parameters are alternative identifiers for the same article rather than both being needed, which is real value. It omits type/format expectations (integer vs UUID string), precedence when both are supplied, and the failure behavior when neither is given.

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 read action on a specific resource: the content language of a `seliee_article`. An agent can distinguish it from get_article or edit_article. It does not explicitly differentiate itself from the sibling language getters (get_page_language, get_collection_language, etc.), but the resource noun is unambiguous.

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?

'Pass `article_id` or `article_uuid`' gives the caller the two lookup routes, which is the main usage decision here. There is no statement of when to prefer this over get_article (which presumably returns the language among other fields), and no note on whether at least one identifier is mandatory given both are schema-optional.

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