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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), and the description adds genuine context on top: test dates are deliberately absent and EPSO supplies them separately, plus the obligation to link to "url" and "official_url" when presenting an offer. That is real behavioral guidance beyond the structured fields.

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, front-loaded with what is returned, followed by the caveat and the citation rule. Tight and waste-free, though the jump from return contents to presentation guidance is slightly abrupt.

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?

An output schema exists, so return values need no elaboration, and the description still helpfully names the key content areas. The main gap is routing guidance against the three sibling tools, which the description leaves implicit. Overall complete enough for a single-parameter read tool.

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 the single parameter already documents both accepted forms (printed reference like "EPSO/AD/427/26" or the site URL). The description adds nothing about the reference parameter itself; the "url"/"official_url" mentions refer to output fields, not input. Baseline 3 applies.

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 gives a specific verb-resource pair ("One competition with its fields, the stage of each, its timeline... and the text of its notice") and enumerates the returned contents. The word "One" implicitly distinguishes it from list_competitions, but no sibling is named explicitly, so an agent must infer the singular-vs-list split.

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?

Usage is implied rather than stated: the description assumes you already have a reference and tells you how to cite the result when presenting an offer. It never says when to reach for this instead of list_competitions or get_vacancy, nor any prerequisite for obtaining a reference.

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