push_value

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

With no annotations, the description carries the full burden. It discloses key behavioral traits: 'Additive — only the target array is touched; siblings and unrelated entries stay intact' and 'Errors if the target isn't an array.' This goes beyond a simple purpose statement, though it does not discuss permissions or return format, which is acceptable for a simple mutation tool.

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 three sentences, front-loaded with the primary action, followed by behavioral transparency and usage guidance. Every sentence earns its place; there is no repetition of schema details or filler. It is concise and well-structured.

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?

Given the tool's moderate complexity (6 params) and lack of annotations or output schema, the description covers the essential context: purpose, side effects, error condition, and relationship to a sibling tool. It does not explain return values or the prompt-collapse behavior, but those are documented in the schema. Overall, the description is sufficiently complete for an agent to select and invoke the tool 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%, so the baseline is 3. The description adds general context about nested paths and array-shaped properties, but does not add specific parameter-level meaning beyond what the schema already provides. The schema fully documents all six parameters, so the description's contribution here is minimal but not absent.

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 opens with a clear, specific verb+resource: 'Append a value to an array at a nested path.' This precisely identifies the action and target, and differentiates from siblings by explicitly recommending this tool over set_property for additive array appends. It leaves no ambiguity about what the tool does.

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 provides explicit guidance: 'Use this instead of set_property for adding items to a DATA prime's value (or any other array-shaped property).' This names a specific alternative and the condition under which this tool should be chosen. The 'additive' qualifier and error condition ('Errors if the target isn't an array') further clarify when it is appropriate.

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