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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely non-structured behavior: it is safe to call directly and sign-in is handled by the app rather than the agent. That auth-handling detail is the main value-add, though rate limits or empty-result behavior are not addressed.

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, zero filler: the trigger and scope come first, the invocation/auth note second. Every clause earns its place and nothing is repeated from the title.

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 zero-required-param read tool with a fully documented schema and no output schema, the description covers trigger, scope, and auth handling. It lightly sketches returns ('status and links') but says nothing about what an empty result means or result count, which is a minor gap rather than a blocking one.

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 'language' parameter already documents its enum and the 'use the user's language' guidance. The description adds no additional meaning about the parameter, 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 resource and scope: the caller's own applications and purchase interests, returning status and links. The word 'own' plus the phrasing separates it from write-side siblings like register_purchase_interest and apply_for_listing. Multilingual trigger phrases (meine Bewerbungen, mes candidatures) add retrieval-specific disambiguation.

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?

Gives a clear usage trigger ('when someone asks about their own applications or purchase interests') and even tells the agent how to invoke it. It stops short of naming exclusions or an alternative tool for application history versus, say, listing enquiries, so it is clear context without explicit when-not guidance.

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