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

readOnlyHint=true already covers the safety profile, but the description adds real context beyond it: the tool returns null when a character has no style sheet, it reports a staleness flag, and it is explicitly 'Free' (no cost/credit). What it does not disclose is whether the style sheet is fetched from a generated artifact versus computed live, or any failure mode for bad ids.

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?

One front-loaded sentence enumerating the return payload, followed by two clipped fragments ('A character without one returns null. Free.'). Every element carries information and nothing is padding, though the telegraphic 'Free.' fragment is stylistically rough and the enumeration of fields runs slightly long.

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 two-param read tool with no output schema, the description does the necessary job of summarizing what comes back (views, style kit, approved, veraltet) and the empty case (null). The remaining gap is a positive definition of 'veraltet' — how staleness is determined — which an agent would need to interpret the flag correctly.

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%, with both required params (project_id, character_id) documented in the schema down to the 'positive integer as string' format and a cross-reference to lab_list_characters. The description mentions 'in this project' and 'this character' only obliquely and adds no format or constraint detail, so the schema does all the work — baseline 3.

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 and resource ('Show this character's style sheet in this project') and enumerates the contents returned: views, carried style kit, approval state, and a 'veraltet' staleness flag. That is clear and distinguishable from the mutation siblings lab_stilblatt_erzeugen/freigeben/verwerfen by the verb alone, though it never names the potentially overlapping lab_get_character_sheet.

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 only implied: 'Show ... in this project' plus the null-return note tells the agent this is a per-character read inside a project. There is no explicit when-to-use versus lab_get_character_sheet, lab_list_stil_kits, or lab_stilblatt_freigeben/verwerfen, and no stated prerequisite such as whether a style sheet must already have been generated.

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