Marketplace index seed

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

Annotations already mark it as not read-only and destructive, and the description adds critical behavioral context: it writes a file, has a guard, and defaults to not overwriting (overwrite=false protects existing files). This goes beyond the annotation flags and helps the agent predict side effects. However, it does not disclose what happens on conflict beyond failing, which is implicit.

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 primary action, and each sentence provides distinct valuable information (purpose/features, then usage/guard). No redundant phrases.

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 output schema exists, the description doesn't need to detail return values. It covers the tool's purpose, timing relative to a sibling, and the file-safety guard. The remaining parameter details are available in the schema, so the description is sufficient for an agent to understand the tool's role and safe invocation, though it could explicitly mention the failure behavior on existing files for absolute completeness.

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 only 60% schema description coverage, the description compensates partially by referencing three key parameters: 'built-in seed entries' maps to include_builtin_starters, 'custom package entries' to entries, and it explicitly explains overwrite=false protects existing files. It does not mention the `name` parameter, but the schema covers that with a default. Overall, it clarifies the main functional parameters beyond schema alone.

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 specific verb and resource ('Write a guarded starter marketplace index JSON') and immediately distinguishes from the sibling tool (`local_marketplace_index`) by specifying this is the preparatory step. It clearly identifies the tool's output and its role in marketplace setup.

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 second sentence gives explicit timing ('before local_marketplace_index') and scenario ('when planning a local package marketplace'), naming the alternative sibling tool. This tells the agent exactly when to choose this tool over others.

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