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

readOnlyHint=true already declares this as a safe read, so the bar is lower. The description adds a small piece of return context by noting the vat_rate is included with both a name and a rate example, but says nothing about other returned fields or behavior on a missing id.

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?

A single front-loaded sentence that identifies the resource first and the notable returned field second; no filler. The parenthetical vat_rate example is slightly padded but earns its place as disambiguation.

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?

There is no output schema, so the description carries the burden of describing the return value, yet it only mentions vat_rate out of what is presumably a larger product record (name, price, unit). Adequate but incomplete for a get-by-id 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 id parameter already documents itself as 'Proposition id (from papierkram_list_propositions)'. The description adds no further semantics, so the 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?

States a specific verb ('Get') and resource ('one stored product or service'), which is clearly distinguishable from the get_* siblings for invoices, persons, projects, etc. It does not use the API term 'proposition' that the tool name and list_propositions sibling use, so an agent must infer the product/service = proposition mapping.

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 gives no when-to-use guidance, no exclusions, and never points to papierkram_list_propositions (only the schema parameter text does). An agent gets no explicit routing rule beyond 'this fetches one item'.

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