update_egg_variable

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

The description adds valuable behavioral context beyond annotations: it clarifies that 'All fields are optional - only provided fields will be changed' (partial update behavior) and specifies the authentication requirement ('Requires Application API key'). While annotations already indicate destructiveHint=true and openWorldHint=true, the description provides practical implementation details that help the agent understand how to use the tool correctly.

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 extremely efficient - three sentences that each serve distinct purposes: stating the action, explaining update behavior, and providing prerequisites. There's zero wasted text, and the most critical information (the tool's purpose) appears first.

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 destructive mutation tool with 10 parameters and no output schema, the description provides excellent context about authentication requirements, partial update behavior, and discovery prerequisites. The main gap is the lack of information about return values or error conditions, but given the comprehensive parameter documentation in the schema and clear behavioral guidance, this is reasonably complete.

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?

With 100% schema description coverage, the input schema already documents all 10 parameters thoroughly. The description doesn't add significant parameter semantics beyond what's in the schema, though it does imply the partial update behavior ('only provided fields will be changed') which relates to parameter usage. This meets the baseline expectation for high schema coverage.

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 clearly states the specific action ('Update an existing environment variable on an egg') and resource ('environment variable'), distinguishing it from siblings like 'create_egg_variable' and 'delete_egg_variable'. It also specifies this is an 'admin action', adding important context about required permissions.

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 on when to use this tool ('Use list_egg_variables to find the variable_id') and prerequisites ('Requires Application API key'). It also distinguishes it from the 'list_egg_variables' sibling tool for discovery purposes.

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