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

Annotations already declare destructiveHint=false and readOnlyHint=false. The description adds the key behavioral detail that it appends to existing entries and deletes nothing, which clarifies the additive nature beyond the binary destructive hint. It does not cover idempotency explicitly, though the annotation covers it.

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?

The description is front-loaded with the core action, then adds behavioral and usage context in short sentences. The trailing '| EN: allowlist, permission, whitelist, code' keywords are slightly extraneous for an agent but do not significantly harm readability.

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 full schema parameter descriptions, clear annotations, and no output schema, the description is complete enough for an agent to call the tool correctly. It covers purpose, usage conditions, alternatives, and the additive behavior.

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%, so all three parameters are fully documented in the schema itself. The description mentions email addresses and patterns but adds no syntax or format details beyond what the schema already provides, so the baseline of 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 states a specific verb and resource: adding a single email address or pattern to a code's allowlist. It explicitly distinguishes itself from sibling tools by naming upload_code_allowlist for bulk additions and delete_code_allowlist_entry for removal.

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?

It gives explicit when-to-use guidance ('fuer einzelne Nachzuegler') and names the alternative for bulk operations ('fuer viele Adressen ist der Excel-Upload upload_code_allowlist der richtige Weg'). It also points to the removal tool, leaving no ambiguity about tool selection.

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