apex_add_timeline

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

The description discloses that the tool adds a region and requires the SQL to return specific column aliases, which is a key behavioral constraint. Annotations are all false and provide no additional safety information, so the description carries the burden. It does not mention side effects, permissions, or undo behavior, but for a simple additive tool this is minimal but acceptable.

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 two sentences, front-loaded with the core action, and contains zero filler. Every word earns its place, making it an excellent example of conciseness.

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 has 8 parameters with complete schema descriptions and a declared output schema, the description need not explain return values. The main gap is lack of usage guidance relative to sibling region tools, but the schema and the stated SQL requirement together provide enough information for correct invocation. Slightly below perfect due to missing alternative guidance.

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 schema fully documents all parameters. The description's SQL column requirement adds marginal value by connecting sql_query to date_col, title_col, and body_col, but this is largely redundant with the schema descriptions. No additional parameter meaning is provided beyond the schema.

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 uses a specific verb and resource: 'Add a vertical timeline region.' This clearly distinguishes it from sibling tools like apex_add_calendar or apex_add_activity_stream. The required SQL columns are also stated, further clarifying the tool's specific purpose.

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 implies usage when a timeline region is needed, and the SQL requirement provides a prerequisite. However, it does not explicitly mention when to use this over generic region tools (e.g., apex_add_region) or provide exclusion criteria. No alternatives are named.

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