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

The description goes well beyond the annotations by disclosing that omitted nullable means required at enrichment, that adding inside $defs affects every usage site, and that the tool follows the same validation and working-copy/publication rules as update_schema_property. These are meaningful behavioral side effects an agent needs to know.

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 information-dense but every sentence earns its place: primary operation, accepted values, prerequisites, side effects, and reference to documentation. It is front-loaded with the most important scoping information and contains no filler.

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 mutation tool with an output schema and rich annotations, the description covers prerequisites, permissions, side effects, and cross-tool references. It even points to the property format documentation. Nothing essential for invoking the tool correctly is missing.

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?

The input schema already covers 100% of parameters, so the baseline is 3. The description adds extra semantics beyond the schema by explaining accepted definition forms (scalar, nested object, reference to $defs or $enums) and the nullable default behavior, which helps the agent construct valid input.

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 ('Add a property') and immediately scopes where it applies: root, object path, or '$defs.X'. It also distinguishes the operation from siblings like update_schema_property and move_schema_property by focusing on the act of adding, not modifying or moving.

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 clear usage context: requires editor, no LLM call, read the container with get_schema_part first, and the same validation/publication rules as update_schema_property apply. It does not explicitly state exclusions or name alternatives for when to use update instead of add, but the purpose is clear enough for an agent to select it correctly.

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