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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: results include the slug and a flag for whether a detailed Nebenkosten profile exists (only for the 400 largest cities), which shapes what the agent can expect back. It does not describe pagination or ranking, so not a 5.

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?

Front-loaded with purpose, then the ambiguity rationale and the return-value hint, all in three compact sentences. The appended English translation duplicates content, which is redundant for a German-capable agent, but it costs little and does not bury the core message.

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?

With no output schema, the description must carry return-value meaning, and it does: slug plus profile-availability flag. Combined with the annotations, an agent has enough to call it correctly; only result ordering and the 'limit' parameter's effect remain unaddressed.

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 50%: 'query' is documented in the schema, but 'limit' has no description anywhere. The description implies name/prefix matching but adds no format or syntax detail beyond the schema's own example. Baseline 3 for a half-documented schema is appropriate.

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 ('Sucht deutsche Städte und Gemeinden nach Namen') plus the concrete return artifact (the slug other tools consume). This distinguishes it immediately from siblings like get_city_costs or get_property_tax_rate, which consume rather than produce the slug.

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?

Explicitly frames the use case: resolving ambiguous names (the 'Neuenkirchen' example) and feeding slugs to the other tools, which effectively makes it the entry point of the chain. It stops short of stating exclusions or naming which sibling to use when, but the context is clear enough to route correctly.

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